This study is for a small sized library to expand the functions of public libraries in the community. This study aims to encourage local residents utilizing information and public libraries by opening parted facilities to public and naming it a substitute. It is expected to contribute to richer welfare system. In detail, the study discusses progression of the small sized library as well as budgeting and hiring staffs in Committee on Library and Policy. However, there is limitations in terms of capabilities because school library is different from public library target users, space, unit plans. Therefore, this study investigates a small sized library as a function to find out type, plan, and space availability and size of ideal open school library.