For a traditional school library, there was an image of "Closed Facility" to students and and children. In this paper, the author has surveyed how a future school library should be by mingling of the students, children and teachers with the three elements of 'data', 'facilities' and 'staff'. Only when these three elements become substantial, a better school library is built up. First of all, as the first step to 'ensure both a rich learning for students and children, and the encounter with books', the key to school library changed to a 'closed facility' should be unlocked. What is important to a future school library is to have a mutual understanding of 'a school library is a place of a door everywhere' where every citizen can touch all kinds of the world.