This study is attempt to find out the justification of the contracting-out for public library considering by the results from estimation about public service governed through contacting-out. For this study I made use of both integrated estimation of public services and evaluation of library service, which have beeing managed by contracting-out. Finally, I realized that attempting the contracting-out for public library may has many limitations due to the characteristics of library service and the failure to achieve the satisfaction of hon in public service.