PURPOSE: To provide a paper sheet alignment device ensuring a paper sheet for image formation to be free from deformation and improper alignment.

CONSTITUTION: A paper sheet alignment device having a pair of alignment members 3 in contact with both sides of a paper sheet 4 for the alignment thereof in a stacking direction, is equipped with a plurality of guide members 2 (2a to 2d) travelling in an interlocked condition along the same direction around a rotary shaft 1, as well as the alignment members 3 having engagement sections 3a for engagement with the guide members 2 and vertical planes 3b coming in plane contact with the side of the paper sheet 4. Also, the vertical planes 3b of the members 3 are positioned so as to oppose both sides of the sheet 4 for the array thereof in a stacking direction.