diff --git a/src/main/java/com/ntlab/irisserver/entities/Member.java b/src/main/java/com/ntlab/irisserver/entities/Member.java
index 68fc6ff..1afa6df 100644
--- a/src/main/java/com/ntlab/irisserver/entities/Member.java
+++ b/src/main/java/com/ntlab/irisserver/entities/Member.java
@@ -23,7 +23,7 @@
     }
 
     //-----------------------------------------------------------------
-    // setter0
+    // setter
     public void setNickname(String nickname) {this.nickname = nickname;}
 
     public void setBelongs(String belongs) {this.belongs = belongs;}
diff --git a/src/main/java/com/ntlab/irisserver/entities/Room.java b/src/main/java/com/ntlab/irisserver/entities/Room.java
index b1e0896..bb7ccb1 100644
--- a/src/main/java/com/ntlab/irisserver/entities/Room.java
+++ b/src/main/java/com/ntlab/irisserver/entities/Room.java
@@ -82,32 +82,34 @@
 
                 }
 
-                //マスターを変更
-                if(belongs.equals("r")) {
 
-                        //赤チームのマスターをメンバーに変更
-                        if(redMaster != null) {
-                                redMaster.setMaster(false);
+                if(isMaster == true){
+                        //マスターを変更
+                        if(belongs.equals("r")) {
+
+                                //赤チームのマスターをメンバーに変更
+                                if(redMaster != null) {
+                                        redMaster.setMaster(false);
+                                }
+
+                                //変更対象を赤チームのマスターに変更
+                                m.setMaster(true);
+                                redMaster = m;
                         }
 
-                        //変更対象を赤チームのマスターに変更
-                        m.setMaster(true);
-                        redMaster = m;
-                }
+                        if(belongs.equals("b")) {
 
-                if(belongs.equals("b")) {
+                                //青チームのマスターをメンバーに変更
+                                if(blueMaster != null) {
+                                        blueMaster.setMaster(false);
+                                }
 
-                        //青チームのマスターをメンバーに変更
-                        if(blueMaster != null) {
-                                blueMaster.setMaster(false);
+                                //変更対象を赤チームのマスターに変更
+                                m.setMaster(true);
+                                blueMaster = m;
                         }
-
-                        //変更対象を赤チームのマスターに変更
-                        m.setMaster(true);
-                        blueMaster = m;
                 }
-
-
+                
         }
 
         public Game createGame(String owner) {