diff --git a/src/main/java/org/ntlab/tampoposerver/models/ChatRooms.java b/src/main/java/org/ntlab/tampoposerver/models/ChatRooms.java
index eae2bce..71e8b36 100644
--- a/src/main/java/org/ntlab/tampoposerver/models/ChatRooms.java
+++ b/src/main/java/org/ntlab/tampoposerver/models/ChatRooms.java
@@ -48,7 +48,7 @@
         return new ArrayList<>(users);
     }
 
-    public void put(Integer chatRoomId, String chatRoomNumber) {
+    public void put(String chatRoomId, String chatRoomNumber) {
     }
 
 //    public Integer updateMessage() {
diff --git a/src/main/java/org/ntlab/tampoposerver/repositories/ChatRoomsRepository.java b/src/main/java/org/ntlab/tampoposerver/repositories/ChatRoomsRepository.java
index ae1ac40..a64975a 100644
--- a/src/main/java/org/ntlab/tampoposerver/repositories/ChatRoomsRepository.java
+++ b/src/main/java/org/ntlab/tampoposerver/repositories/ChatRoomsRepository.java
@@ -8,13 +8,13 @@
 
 @Repository
 public class ChatRoomsRepository {
-    private final HashMap<Integer, ChatRooms> chatRooms = new HashMap<>();
-    private int id = 0;
+    private final HashMap<String, ChatRooms> chatRooms = new HashMap<>();
+    private int id = 0; // 数字でカウントしてStringに変換
 
     // 新しいチャットルーム作成（空のメッセージリスト付き）
     public ChatRooms addChatRoom(String user0Id, String user1Id) {
         ChatRooms chatRoom = new ChatRooms(Integer.toString(id), user0Id, user1Id);
-        chatRooms.put(id, chatRoom);
+        chatRooms.put(Integer.toString(id), chatRoom);
         id++;
         return chatRoom;
     }
@@ -49,7 +49,7 @@
 
 
     // ユーザーを既存チャットルームに追加（例：グループチャット用）
-    public ChatRooms addUserRoom(int chatRoomId, String userId) {
+    public ChatRooms addUserRoom(String chatRoomId, String userId) {
         ChatRooms chatRoom = chatRooms.get(chatRoomId);
         if (chatRoom == null) return null;
 
@@ -67,7 +67,7 @@
 //    }
 
     //メッセージを取得
-    public List<ChatRooms.Message> getMessagesFromUser(int chatRoomId, String userId) {
+    public List<ChatRooms.Message> getMessagesFromUser(String chatRoomId, String userId) {
         ChatRooms chatRoom = chatRooms.get(chatRoomId);
         if (chatRoom == null) return null;
 
@@ -78,7 +78,7 @@
     }
 
     // 新しいメッセージを追加
-    public ChatRooms addMessage(int chatRoomId, String senderId, String content) {
+    public ChatRooms addMessage(String chatRoomId, String senderId, String content) {
         ChatRooms chatRoom = chatRooms.get(chatRoomId);
         if (chatRoom == null) return null;
 
@@ -87,19 +87,19 @@
     }
 
     // 既存メッセージを更新
-    public ChatRooms updateMessage(int chatRoomId, String userId, String newContent) {
+    public ChatRooms updateMessage(String chatRoomId, String userId, String newContent) {
         ChatRooms chatRoom = chatRooms.get(chatRoomId);
         if (chatRoom == null) return null;
 
-        return chatRoom.updateMessage(Integer.toString(chatRoomId), userId, newContent);
+        return chatRoom.updateMessage(chatRoomId, userId, newContent);
     }
 
     // チャットルーム削除
-    public ChatRooms deleteChatRoom(int chatRoomId) {
+    public ChatRooms deleteChatRoom(String chatRoomId) {
         return chatRooms.remove(chatRoomId);
     }
 
-    public ChatRooms getChatRoom(int chatRoomId) {
+    public ChatRooms getChatRoom(String chatRoomId) {
         return chatRooms.get(chatRoomId);
     }
 
diff --git a/src/main/java/org/ntlab/tampoposerver/resources/ChatRoomsResource.java b/src/main/java/org/ntlab/tampoposerver/resources/ChatRoomsResource.java
index f581109..67ac702 100644
--- a/src/main/java/org/ntlab/tampoposerver/resources/ChatRoomsResource.java
+++ b/src/main/java/org/ntlab/tampoposerver/resources/ChatRoomsResource.java
@@ -121,7 +121,7 @@
     @GET
     @Path("/{chat-room-id}/{user-id}")
     @Produces(MediaType.APPLICATION_JSON)
-    public Response getChatRoomMessages(@PathParam("chat-room-id") int chatRoomId, @PathParam("user-id") String userId, @QueryParam("token") String token) {
+    public Response getChatRoomMessages(@PathParam("chat-room-id") String chatRoomId, @PathParam("user-id") String userId, @QueryParam("token") String token) {
         User user = userRepository.getUser(userId);
         if (user == null) throw new NotFoundException("ユーザーが見つかりません");
         List<ChatRooms.Message> messages = chatRoomsRepository.getMessagesFromUser(chatRoomId, userId);
@@ -146,7 +146,7 @@
     @DELETE
     @Path("/{chatroom-id}/{user-id}")
     @Produces(MediaType.APPLICATION_JSON)
-    public Response leaveChatRoom(@PathParam("chatroom-id") int chatRoomId,
+    public Response deleteChatRoom(@PathParam("chatroom-id") String chatRoomId,
                                   @PathParam("user-id") String userId,
                                   @QueryParam("token") String token) {
 
@@ -187,7 +187,7 @@
     @Path("/{chatroom-id}/{user-id}")
     @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
     @Produces(MediaType.APPLICATION_JSON)
-    public Response addChatRoomUser(@PathParam("chatroom-id") int chatRoomId, @PathParam("user-id") String userId, @QueryParam("token") String token) {
+    public Response addChatRoomUser(@PathParam("chatroom-id") String chatRoomId, @PathParam("user-id") String userId, @QueryParam("token") String token) {
         User user = userRepository.getUser(userId);
         if (user == null) {
             throw new NotFoundException("IDが存在しません");
@@ -213,7 +213,7 @@
     @Path("/{chatroom-id}/{user-id}/message")
     @Consumes(MediaType.APPLICATION_FORM_URLENCODED)
     @Produces(MediaType.APPLICATION_JSON)
-    public Response updateMessage(@PathParam("chatroom-id") int roomId, @PathParam("user-id") String userId, @FormParam("message") String message, @QueryParam("token") String token) {
+    public Response updateMessage(@PathParam("chatroom-id") String chatRoomId, @PathParam("user-id") String userId, @FormParam("message") String message, @QueryParam("token") String token) {
         User user = userRepository.getUser(userId);
         if (token == null || !token.equals(user.getToken())) {
             throw new WebApplicationException(
@@ -222,11 +222,11 @@
                             .build()
             );
         }
-        ChatRooms room = chatRoomsRepository.getChatRoom(roomId);
+        ChatRooms room = chatRoomsRepository.getChatRoom(chatRoomId);
         if (room == null) throw new NotFoundException("チャットルームが存在しません");
 
 
-        ChatRooms chatRoom = chatRoomsRepository.addMessage(roomId, userId, message);
+        ChatRooms chatRoom = chatRoomsRepository.addMessage(chatRoomId, userId, message);
         return Response.status(Response.Status.OK).entity(chatRoom).build();
     }