To decrease pull-out resistance of a strip material by providing a guide mans with a contact prevention means for preventing contact with the strip material which inclines accompanying the turn of a stack to a binding position.

In the inside bottom of a fixing guide 44a, a recess 44c whose width is approximately half the width of it is made, and also in the movable part 44b, a notch 44d is made. A contact prevention means for preventing contact with a strip material B is composed of the recess 44c of the inside bottom of the fixing guide 44a and the notch 44d of the movable guide 44b. According to the composition, because one side of the strip material B that inclines accompanying the turn of a stack of plates to a binding position is positioned into the recess 44c and the other side into the notch 44d by the provision of the recess 44c in the inside bottom of the fixing guide 44a and the notch 44d in the movable guide 44b, the contact of the strip material B with the fixing guide 44a and movable guide 44b can be prevented and pull-out resistance of the strip material can, therefore, be decreased.