PURPOSE: To obtain accurately and easily a copy having a binding margin from an original which is set as normal, only with the operation of a knob by providing the binding margin setting knob.

CONSTITUTION: In case of a copy which does not require a binding margin, the original is matched to a positioning guide 21, and a platen cover 13 is allowed to fall, and copying is performed. In case of a copy requiring a binding margin, a binding margin setting knob 20 is moved for an extent corresponding to the set binding margin after falling of the cover 13. In accordance with this movement, slide plate 14, an original retaining member 15, and the original are moved for the same extent accurately as one body. Since a guide depressing projection provided at the front end of the cover 13 presses the guide 21 downward before movement, the member 15 and the original are moved smoothly without hindrance. Copying is performed thereafter, and thus, the copy having the binding margin in one side is obtained accurately.