To enable to perform an accumulating operation and a binding operation for bills in parallel.

A paper sheet processing apparatus is equipped with an accumulating part 26 for accumulating the bills, a carrying mechanism 28 for carrying accumulated bills accumulated by this accumulating part 26, and a binding part 30 for binding the accumulated bills carried by this carrying mechanism 28. The carrying mechanism 28 has a carrying belt 44 endlessly running in one direction, and a plurality of receiving boxes 51 arranged at specified intervals over the running direction on this carrying belt 44. After one of the receiving boxes 51 is carried by running the carrying belt 44, and the bills with a specified number of sheets are accumulated, it is carried to the binding part 30 and the bills are bound, and during this binding, a following empty receiving box 51 is positioned at the accumulating part 26, where the bills are accumulated.