Punches 44 of punchers 41a to 41d each punch a plate P lying immediately thereunder to form a notch. Then, stopper pins 47 of the punchers 41c and 41d abut with the deepest portion of the notch, such that the plate P is further inserted. The punches 44 of the punchers 41a and 41b each punch the plate P lying immediately thereunder to form a deeper notch. In other words, the puncher 41 is capable of forming notches of different depths along one end face of the plate P, whereby it is possible to realize various methods for positioning the plate P on the recording drum 5 in a suitable manner.