diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 34d6d08..ab93a07 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -5,6 +5,7 @@ plugins {
     alias(libs.plugins.kotlin.android)
     alias(libs.plugins.kotlin.compose)
     alias(libs.plugins.kotlin.serialization)
+    alias(libs.plugins.ksp)
 }
 
 android {
@@ -59,6 +60,10 @@ dependencies {
     implementation(libs.androidx.navigation3.runtime)
     implementation(libs.androidx.navigation3.ui)
 
+    implementation(libs.androidx.room.runtime)
+    implementation(libs.androidx.room.ktx)
+    ksp(libs.androidx.room.compiler)
+
     testImplementation(libs.junit)
 
     androidTestImplementation(libs.androidx.junit)
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 5778b11..008908c 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -3,6 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <application
+        android:name=".TomatoApplication"
         android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
         android:fullBackupContent="@xml/backup_rules"
diff --git a/app/src/main/java/org/nsh07/pomodoro/TomatoApplication.kt b/app/src/main/java/org/nsh07/pomodoro/TomatoApplication.kt
new file mode 100644
index 0000000..b0e144f
--- /dev/null
+++ b/app/src/main/java/org/nsh07/pomodoro/TomatoApplication.kt
@@ -0,0 +1,13 @@
+package org.nsh07.pomodoro
+
+import android.app.Application
+import org.nsh07.pomodoro.data.AppContainer
+import org.nsh07.pomodoro.data.DefaultAppContainer
+
+class TomatoApplication : Application() {
+    lateinit var container: AppContainer
+    override fun onCreate() {
+        super.onCreate()
+        container = DefaultAppContainer(this)
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/org/nsh07/pomodoro/data/AppContainer.kt b/app/src/main/java/org/nsh07/pomodoro/data/AppContainer.kt
new file mode 100644
index 0000000..2101cb2
--- /dev/null
+++ b/app/src/main/java/org/nsh07/pomodoro/data/AppContainer.kt
@@ -0,0 +1,17 @@
+package org.nsh07.pomodoro.data
+
+import android.content.Context
+
+interface AppContainer {
+    val appPreferencesRepository: AppPreferenceRepository
+}
+
+class DefaultAppContainer(context: Context) : AppContainer {
+
+    override val appPreferencesRepository: AppPreferenceRepository by lazy {
+        AppPreferenceRepository(
+            AppDatabase.getDatabase(context).preferenceDao()
+        )
+    }
+
+}
\ No newline at end of file
diff --git a/app/src/main/java/org/nsh07/pomodoro/data/AppDatabase.kt b/app/src/main/java/org/nsh07/pomodoro/data/AppDatabase.kt
new file mode 100644
index 0000000..96b8130
--- /dev/null
+++ b/app/src/main/java/org/nsh07/pomodoro/data/AppDatabase.kt
@@ -0,0 +1,29 @@
+package org.nsh07.pomodoro.data
+
+import android.content.Context
+import androidx.room.Database
+import androidx.room.Room
+import androidx.room.RoomDatabase
+
+@Database(
+    entities = [IntPreference::class],
+    version = 1
+)
+abstract class AppDatabase : RoomDatabase() {
+
+    abstract fun preferenceDao(): PreferenceDao
+
+    companion object {
+
+        @Volatile
+        private var Instance: AppDatabase? = null
+
+        fun getDatabase(context: Context): AppDatabase {
+            return Instance ?: synchronized(this) {
+                Room.databaseBuilder(context, AppDatabase::class.java, "app_database")
+                    .build()
+                    .also { Instance = it }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/org/nsh07/pomodoro/data/Preference.kt b/app/src/main/java/org/nsh07/pomodoro/data/Preference.kt
new file mode 100644
index 0000000..50478aa
--- /dev/null
+++ b/app/src/main/java/org/nsh07/pomodoro/data/Preference.kt
@@ -0,0 +1,11 @@
+package org.nsh07.pomodoro.data
+
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+@Entity(tableName = "int_preference")
+data class IntPreference(
+    @PrimaryKey
+    val key: String,
+    val value: Int
+)
diff --git a/app/src/main/java/org/nsh07/pomodoro/data/PreferenceDao.kt b/app/src/main/java/org/nsh07/pomodoro/data/PreferenceDao.kt
new file mode 100644
index 0000000..3b59976
--- /dev/null
+++ b/app/src/main/java/org/nsh07/pomodoro/data/PreferenceDao.kt
@@ -0,0 +1,19 @@
+package org.nsh07.pomodoro.data
+
+import androidx.room.Dao
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface PreferenceDao {
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertIntPreference(preference: IntPreference)
+
+    @Query("DELETE FROM int_preference")
+    suspend fun resetIntPreferences()
+
+    @Query("SELECT value FROM int_preference WHERE `key` = :key")
+    fun getIntPreference(key: String): Flow<Int?>
+}
\ No newline at end of file
diff --git a/app/src/main/java/org/nsh07/pomodoro/data/PreferenceRepository.kt b/app/src/main/java/org/nsh07/pomodoro/data/PreferenceRepository.kt
new file mode 100644
index 0000000..bf12c5a
--- /dev/null
+++ b/app/src/main/java/org/nsh07/pomodoro/data/PreferenceRepository.kt
@@ -0,0 +1,31 @@
+package org.nsh07.pomodoro.data
+
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.withContext
+
+interface PreferencesRepository {
+    suspend fun saveIntPreference(key: String, value: Int)
+
+    fun getIntPreference(key: String): Flow<Int?>
+
+    suspend fun resetSettings()
+}
+
+class AppPreferenceRepository(
+    private val preferenceDao: PreferenceDao,
+    private val ioDispatcher: CoroutineDispatcher = Dispatchers.IO
+): PreferencesRepository {
+    override suspend fun saveIntPreference(key: String, value: Int) =
+        withContext(ioDispatcher) {
+            preferenceDao.insertIntPreference(IntPreference(key, value))
+        }
+
+    override fun getIntPreference(key: String): Flow<Int?> =
+        preferenceDao.getIntPreference(key)
+
+    override suspend fun resetSettings() = withContext(ioDispatcher) {
+        preferenceDao.resetIntPreferences()
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/org/nsh07/pomodoro/ui/AppScreen.kt b/app/src/main/java/org/nsh07/pomodoro/ui/AppScreen.kt
index afbfb1e..c54ac8c 100644
--- a/app/src/main/java/org/nsh07/pomodoro/ui/AppScreen.kt
+++ b/app/src/main/java/org/nsh07/pomodoro/ui/AppScreen.kt
@@ -40,7 +40,7 @@ import org.nsh07.pomodoro.ui.viewModel.UiViewModel
 @Composable
 fun AppScreen(
     modifier: Modifier = Modifier,
-    viewModel: UiViewModel = viewModel()
+    viewModel: UiViewModel = viewModel(factory = UiViewModel.Factory)
 ) {
     val uiState by viewModel.uiState.collectAsStateWithLifecycle()
     val remainingTime by viewModel.time.collectAsStateWithLifecycle()
diff --git a/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiViewModel.kt b/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiViewModel.kt
index ef54923..a423b7c 100644
--- a/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiViewModel.kt
+++ b/app/src/main/java/org/nsh07/pomodoro/ui/viewModel/UiViewModel.kt
@@ -2,7 +2,11 @@ package org.nsh07.pomodoro.ui.viewModel
 
 import android.os.SystemClock
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.ViewModelProvider.AndroidViewModelFactory.Companion.APPLICATION_KEY
 import androidx.lifecycle.viewModelScope
+import androidx.lifecycle.viewmodel.initializer
+import androidx.lifecycle.viewmodel.viewModelFactory
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -10,10 +14,14 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
+import org.nsh07.pomodoro.TomatoApplication
+import org.nsh07.pomodoro.data.AppPreferenceRepository
 import java.util.Locale
 import kotlin.math.ceil
 
-class UiViewModel : ViewModel() {
+class UiViewModel(
+    private val preferenceRepository: AppPreferenceRepository
+) : ViewModel() {
     val focusTime = 25 * 60 * 1000
     val shortBreakTime = 5 * 60 * 1000
     val longBreakTime = 15 * 60 * 1000
@@ -153,6 +161,8 @@ class UiViewModel : ViewModel() {
                                 )
                             }
                         }
+
+                        toggleTimer()
                     } else {
                         _uiState.update { currentState ->
                             currentState.copy(
@@ -172,4 +182,14 @@ class UiViewModel : ViewModel() {
         val sec = (ceil(t / 1000.0).toInt() % 60)
         return String.format(locale = Locale.getDefault(), "%02d:%02d", min, sec)
     }
+
+    companion object {
+        val Factory: ViewModelProvider.Factory = viewModelFactory {
+            initializer {
+                val application = (this[APPLICATION_KEY] as TomatoApplication)
+                val appPreferenceRepository = application.container.appPreferencesRepository
+                UiViewModel(preferenceRepository = appPreferenceRepository)
+            }
+        }
+    }
 }
\ No newline at end of file
diff --git a/build.gradle.kts b/build.gradle.kts
index 5ba8ae0..f370cb1 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -4,4 +4,5 @@ plugins {
     alias(libs.plugins.kotlin.android) apply false
     alias(libs.plugins.kotlin.compose) apply false
     alias(libs.plugins.kotlin.serialization) apply false
+    alias(libs.plugins.ksp) apply false
 }
\ No newline at end of file
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index d7e6a71..21cfb54 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,37 +1,43 @@
 [versions]
+activityCompose = "1.10.1"
 agp = "8.11.0"
-kotlin = "2.2.0"
+composeBom = "2025.06.02"
 coreKtx = "1.16.0"
+espressoCore = "3.6.1"
 junit = "4.13.2"
 junitVersion = "1.2.1"
-espressoCore = "3.6.1"
+kotlin = "2.2.0"
+ksp = "2.2.0-2.0.2"
 lifecycleRuntimeKtx = "2.9.1"
-activityCompose = "1.10.1"
-composeBom = "2025.06.02"
 navigation3Runtime = "1.0.0-alpha05"
+room = "2.7.2"
 
 [libraries]
-androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
-androidx-lifecycle-viewmodel = { module = "androidx.lifecycle:lifecycle-viewmodel", version.ref = "lifecycleRuntimeKtx" }
-androidx-lifecycle-viewmodel-compose = { module = "androidx.lifecycle:lifecycle-viewmodel-compose", version.ref = "lifecycleRuntimeKtx" }
-androidx-navigation3-runtime = { module = "androidx.navigation3:navigation3-runtime", version.ref = "navigation3Runtime" }
-androidx-navigation3-ui = { module = "androidx.navigation3:navigation3-ui", version.ref = "navigation3Runtime" }
-junit = { group = "junit", name = "junit", version.ref = "junit" }
-androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
-androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
-androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntimeKtx" }
 androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }
 androidx-compose-bom = { group = "androidx.compose", name = "compose-bom-alpha", version.ref = "composeBom" }
+androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
+androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
+androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
+androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycleRuntimeKtx" }
+androidx-lifecycle-viewmodel = { module = "androidx.lifecycle:lifecycle-viewmodel", version.ref = "lifecycleRuntimeKtx" }
+androidx-lifecycle-viewmodel-compose = { module = "androidx.lifecycle:lifecycle-viewmodel-compose", version.ref = "lifecycleRuntimeKtx" }
+androidx-material3 = { group = "androidx.compose.material3", name = "material3" }
+androidx-navigation3-runtime = { module = "androidx.navigation3:navigation3-runtime", version.ref = "navigation3Runtime" }
+androidx-navigation3-ui = { module = "androidx.navigation3:navigation3-ui", version.ref = "navigation3Runtime" }
+androidx-room-compiler = { module = "androidx.room:room-compiler", version.ref = "room" }
+androidx-room-ktx = { module = "androidx.room:room-ktx", version.ref = "room" }
+androidx-room-runtime = { module = "androidx.room:room-runtime", version.ref = "room" }
 androidx-ui = { group = "androidx.compose.ui", name = "ui" }
 androidx-ui-graphics = { group = "androidx.compose.ui", name = "ui-graphics" }
+androidx-ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4" }
+androidx-ui-test-manifest = { group = "androidx.compose.ui", name = "ui-test-manifest" }
 androidx-ui-tooling = { group = "androidx.compose.ui", name = "ui-tooling" }
 androidx-ui-tooling-preview = { group = "androidx.compose.ui", name = "ui-tooling-preview" }
-androidx-ui-test-manifest = { group = "androidx.compose.ui", name = "ui-test-manifest" }
-androidx-ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4" }
-androidx-material3 = { group = "androidx.compose.material3", name = "material3" }
+junit = { group = "junit", name = "junit", version.ref = "junit" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
 kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
 kotlin-compose = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
 kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin"}
+ksp = { id = "com.google.devtools.ksp", version.ref = "ksp" }