To provide a paper sheet processing device reducing the frequency of jam generation of damaged paper sheets and enhancing the processing capacity by varying a conveying speed for conveying paper sheets according to the degree of damages of the paper sheets to be processed.

Firstly, the soundness/damage discrimination level of a paper sheet bundle Ps to be processed is set by an operation display unit 2 (S40). The conveying speed data is read based on the set soundness/damage discrimination level, the conveying speed is changed based on the read conveying speed data (S42), and the conveying speed is set. The paper sheets are successively taken out from the highest paper sheet P of the paper sheet bundle Ps, and sent at the set conveying speed. The soundness/damage level of the paper sheets P is generated by a paper sheet discrimination unit 50 arranged on a conveying passage. The generated soundness/damage level is added for the paper sheet bundle Ps, and its average soundness/damage level is calculated (S43). The conveying speed data is read based on the calculated average soundness/damage level, and the conveying speed of the next paper sheet bundle Ps is set (S46).