diff --git a/src/main/java/org/ntlab/citrusserver/resources/AccountsRest.java b/src/main/java/org/ntlab/citrusserver/resources/AccountsRest.java
index c21990a..9a6e657 100644
--- a/src/main/java/org/ntlab/citrusserver/resources/AccountsRest.java
+++ b/src/main/java/org/ntlab/citrusserver/resources/AccountsRest.java
@@ -44,9 +44,16 @@
     @Path("/{account_id}")
     @GET
     @Produces(MediaType.APPLICATION_JSON)
-    public Account getAccountInfo(@PathParam("account_id") String accountId){
-            Account ac = accountManager.getAccount(accountId);
-            return ac;
+    public Account getAccountInfo(@PathParam("account_id") String accountId) {
+        //404
+        if (!accountManager.getAccountsID().contains(accountId)){ //account_idが存在しない時
+            var response = Response.status(Response.Status.NOT_FOUND).entity("IDが存在しません");//404
+            throw new WebApplicationException(response.build());
+        }
+
+        Account ac = accountManager.getAccount(accountId);
+        return ac;
+
     }
 
     // アカウント情報を全削除する(DELETE)
@@ -55,9 +62,18 @@
     public void deleteAccount(@PathParam("account_id") String accountId,
                                @QueryParam("token") String token,
                                @QueryParam("password")String password) {
-        if(accountManager.checkToken(accountId, token) == true) {
+        if(accountManager.checkToken(accountId, token)) {
             accountManager.deleteAccount(accountId, token, password);
         }
+        //404
+        if (!accountManager.getAccountsID().contains(accountId)){ //account_idが存在しない時
+            var response = Response.status(Response.Status.NOT_FOUND).entity("IDが存在しません");//404
+            throw new WebApplicationException(response.build());
+        }
+        //403
+        var response = Response.status(Response.Status.FORBIDDEN).entity("アカウント削除失敗");//forbiddenは403
+        throw new WebApplicationException(response.build());
+
     }
 
 
@@ -68,9 +84,16 @@
                                   @FormParam("new_password")String newPassword,
                                   @FormParam("old_password")String oldPassword,
                                   @FormParam("token") String token){
-        if(accountManager.checkToken(accountId, token)== true) {
+        if(accountManager.checkToken(accountId, token)) {
             accountManager.changePassword(accountId, newPassword, oldPassword, token);
         }
+
+        //404
+        if (!accountManager.getAccountsID().contains(accountId)){ //account_idが存在しない時
+            var response = Response.status(Response.Status.NOT_FOUND).entity("IDが存在しません");//404
+            throw new WebApplicationException(response.build());
+        }
+        //403
         var response = Response.status(Response.Status.FORBIDDEN).entity("認証失敗");//forbiddenは403
         throw new WebApplicationException(response.build());
     }
@@ -90,9 +113,15 @@
     public void changeIntroduction(@PathParam("account_id") String accountId,
                                     @FormParam("introduction")String introduction,
                                     @FormParam("token") String token){
-        if(accountManager.checkToken(accountId, token) == true) {
+        if(accountManager.checkToken(accountId, token)) {
             accountManager.changeIntroduction(accountId, introduction, token);
         }
+        //404
+        if (!accountManager.getAccountsID().contains(accountId)){ //account_idが存在しない時
+            var response = Response.status(Response.Status.NOT_FOUND).entity("IDが存在しません");//404
+            throw new WebApplicationException(response.build());
+        }
+        //403
         var response = Response.status(Response.Status.FORBIDDEN).entity("認証失敗");//forbiddenは403
         throw new WebApplicationException(response.build());
     }
@@ -117,6 +146,11 @@
         if(accountManager.checkToken(accountId, token) == true) {
             return accountManager.Favorites(accountId, token);
         }
+        //404
+        if (accountManager.getAccountsID().contains(accountId) == false){ //account_idが存在しない時
+            var response = Response.status(Response.Status.NOT_FOUND).entity("IDが存在しません");//404
+            throw new WebApplicationException(response.build());
+        }
         return null;
     }
 
@@ -130,6 +164,13 @@
         if(accountManager.checkToken(accountId, token) == true) {
             return accountManager.FavoritesBookId(accountId, otherAccountId, token);
         }
+
+        //404
+        if (accountManager.getAccountsID().contains(accountId) == false){ //account_idが存在しない時
+            var response = Response.status(Response.Status.NOT_FOUND).entity("IDが存在しません");//404
+            throw new WebApplicationException(response.build());
+        }
+        //403
         var response = Response.status(Response.Status.FORBIDDEN).entity("認証失敗");//forbiddenは403
         throw new WebApplicationException(response.build());
     }
@@ -149,6 +190,12 @@
     @Path("/{account_id}/login")
     @POST
     public String login(@PathParam("account_id") String accountId,@FormParam("password") String password) {
+        //404
+        if (accountManager.getAccountsID().contains(accountId) == false){ //account_idが存在しない時
+            var response = Response.status(Response.Status.NOT_FOUND).entity("IDが存在しません");//404
+            throw new WebApplicationException(response.build());
+        }
         return accountManager.login(accountId, password);
     }
+
 }