The well-secured library building is essential for providing a better community service for various kinds of public information use and needs. It is a highly respected and commonly used place of one's culture from the far back of the evolution of the civilization. Society development in every means such as economically and culturally depends on the knowledge possessed by its own people. Therefore, the place where the knowledge is stored considered as a monumental place. The term "library building" referred in this book has a very wide and peculiar meaning. This book does not merely consider the construction aspect of the building but discusses the needs to be considered in construction from users and librarians point of view. It must be noted that the term "library building" will readily be judged that it cannot interpret to be an architectural aspect of the building as well. This book is intended to provide some useful information for library personals, students who are learning library designing as well as architects who don't have basic knowledge of library needs and requirements. These three parties, as a team, need to know how important it is to have practical information on library buildings in a book. Each chapter of this book will provide materials as well as practical applications in organizing a library building or converting an existing building to a library.