PURPOSE: To improve the stacking property of a paper by moving a projecting piece which is provided on a rotating body integrated in an entrance roller to a position which does not obstruct the clamping and the carrying of the paper, which is carried in, at the time of a non-inversion mode.

CONSTITUTION: In the non-inversion mode, the entrance roller 17 is rotated in advance of the entering of the paper 2 and a clamp pawl 29 is retreated of the entering of the paper 2 from the receiving position thereof. In such a case, the projecting piece 41 is placed at the position of P1. However, the piece 41 arrives at the position of P2 and pushes out the trailing edge of the paper 2 in the direction of the intermediate tray 7 after the trailing edge of the paper 2 is passed through the nip position of the roller 17. Then, the paper 2 is stacked on the tray 7. Besides, since the piece 41 is moved to the position which does not interfere with the carrying of the paper at the time of inversion, the paper is prevented from being wrinkled, folded, jammed, and being out of the clamp.