diff --git a/src/client/accessor/document.ts b/src/client/accessor/document.ts
index f176160..2fcb9ad 100644
--- a/src/client/accessor/document.ts
+++ b/src/client/accessor/document.ts
@@ -4,16 +4,8 @@ const baseurl = "/api/doc";
 
 export * from "../../model/doc";
 
-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 FetchFailError extends Error{}
+
 export class ClientDocumentAccessor implements DocumentAccessor{
     search: (search_word: string) => Promise<Document[]>;
     addList: (content_list: DocumentBody[]) => Promise<number[]>;
@@ -25,6 +17,7 @@ export class ClientDocumentAccessor implements DocumentAccessor{
     };
     async findList(option?: QueryListOption | undefined): Promise<Document[]>{
         let res = await fetch(`${baseurl}/search?${option !== undefined ? toQueryString(option) : ""}`);
+        if(res.status == 401) throw new FetchFailError("Unauthorized")
         if(res.status !== 200) throw new FetchFailError("findList Failed");
         let ret = await res.json();
         return ret;