diff --git a/app/src/main/java/com/example/sprout/refactor/util/PreferenceUtil.java b/app/src/main/java/com/example/sprout/refactor/util/PreferenceUtil.java
index 8419677..825915f 100644
--- a/app/src/main/java/com/example/sprout/refactor/util/PreferenceUtil.java
+++ b/app/src/main/java/com/example/sprout/refactor/util/PreferenceUtil.java
@@ -26,7 +26,8 @@
 
     public enum Key {
         REGISTERED, // アカウント登録済みかどうか
-        USER_ID // ユーザーid
+        USER_ID, // ユーザーid
+        ROOM_ID // ルームid
     }
 
     public void saveInt(Key key, int value) {
diff --git a/app/src/main/java/com/example/sprout/refactor/viewmodel/RoomListViewModel.java b/app/src/main/java/com/example/sprout/refactor/viewmodel/RoomListViewModel.java
index 91366ac..fab2d23 100644
--- a/app/src/main/java/com/example/sprout/refactor/viewmodel/RoomListViewModel.java
+++ b/app/src/main/java/com/example/sprout/refactor/viewmodel/RoomListViewModel.java
@@ -65,6 +65,7 @@
             public void notify(RoomResponse roomResponse) {
                 if (roomResponse.canEnter()) {
                     // TODO createRoomMainActivity
+                    PreferenceUtil.getInstance().saveInt(PreferenceUtil.Key.ROOM_ID, roomResponse.getRoom().getRoomId());
                 } else {
                     viewContract.showShortToast("入室に失敗しました");
                 }