diff --git a/src/client/accessor/contents.ts b/src/client/accessor/contents.ts
index f8014ea..d35353c 100644
--- a/src/client/accessor/contents.ts
+++ b/src/client/accessor/contents.ts
@@ -3,16 +3,27 @@ import {toQueryString} from './util';
 const baseurl = "/content";
 
 export * from "../../model/contents";
+
+export class FetchFailError implements Error{
+    name: string;
+    message: string;
+    stack?: string;
+    constructor(message:string,stack?:string){
+        this.name = "Fetch Fail";
+        this.message = message;
+        this.stack = stack;
+    }
+}
 export class ClientContentAccessor implements ContentAccessor{
     async findList(option?: QueryListOption | undefined): Promise<Content[]>{
         let res = await fetch(`${baseurl}/search?${option !== undefined ? toQueryString(option) : ""}`);
-        //if(res.status !== 200);
+        if(res.status !== 200) throw new FetchFailError("findList Failed");
         let ret = await res.json();
         return ret;
     }
     async findById(id: number, tagload?: boolean | undefined): Promise<Content | undefined>{
         let res = await fetch(`${baseurl}/${id}`);
-        if(res.status !== 200) return undefined;
+        if(res.status !== 200) throw new FetchFailError("findById Failed");;
         let ret = await res.json();
         return ret;
     }