To provide a paper sheet treatment device which can improve the treatment capacity without increasing the size thereof by improving the operational efficiency.

This paper sheet treatment device comprises a stacking device 41 to stack paper sheets P, a sealing device 42 to bind papers A stacked on the stacking device 41 by a strip B to form a paper sheet bundle H, and a change-over switch 46 to selectively set a stacking mode to only stack the paper sheets P by the stacking device 41 and a sealing mode to bind the papers A stacked by the stacking device 41 by the strip B.