BINDER

PROBLEM TO BE SOLVED: To prevent breakage such as the cut of a hinge end, related to a binder for binding various kinds of documents etc.SOLUTION: The binder includes a first binding member 240 equipped with pipes 245, a second binding member 241 equipped with skewers 246 inserted into and combined with the pipes 245, a pair of side plates 230 and 231 formed of resins for holding the first binding member 240 and the second binding member 241, a bottom plate 220 formed of resin at which the pair of side plates 230 and 231 are rotatable via hinges H and which is integrally molded with each of the pair of side plates 230 and 231, and holding parts which hold either of the first binding member 240 and the second binding member 241 by downside holding portions prepared at the hinge H side and upside holding portions prepared at the opposite side to the hinge H substantially at centers in extension directions of the hinges H in the pair of side plates 230 and 231.