To provide a paper sheet processor capable of stably accumlating and bundling paper sheets by controlling the pressurizing force for pressurizing the accumlated paper sheets according to the quality or condition of the processor.

When the quality or condition of the paper sheets is wrong, the paper sheets are pressurized with the optimal pressurizing force TP by a pusher 42D, and an integration height expected value H of paper sheets P integrated in a temporary integration container is calculated by using a conversion value shown by Figure 7. Then, a rate R of the calculated integration height expected value H to standard integration height Hs is calculated by using a formula (2): R=H/Hs. The pressurizing force TP is set by using a formula (1): TP=TPs+K×R(TPs: pressurizing force when pressurizing the standard integration height Hs by a pusher, K: constant) by using the calculated rate R. Then, the paper sheets are pressurized with the calculated pressurizing force TP by the pusher 42D.