PROBLEM TO BE SOLVED : binder system even more document file can be added, moreover, even in the normal document even with relatively thick booklet together all the document file a new real estate for important document file management. SOLUTION : between the cover 1 and the central longitudinal section 3 shelfback 2 which can be opened and closed in a binder binding fitting 4 is provided in the file, along sides of the holes 7 for the binder has a plurality of binding, the document is inserted and kept 1 made of plastic sheet of the bag body 5 is provided with a plurality of first, second and 1 separately from the bag body 5, and similarly for the binder along sides has a plurality of holes, which document is inserted and kept 2 made of relatively high strength plastic sheet of the bag body 6 and is provided. Selected drawing : fig. 1