To make a paper sheet bundle be hardly peeled off irrespective of a direction to which an external force is applied, in a press-binding device for pressing and binding paper sheets by sandwiching the paper sheet bundle with a pair of uneven members.

Uneven members have a plurality of parts in which a plurality of recesses and a plurality of protrusions are alternately arranged parallel. The plurality of parts form a groove group 11 composed of a plurality of parallel grooves and groove groups 12 and 13 in a direction orthogonal to the groove group 11 in a binding part 10 of a paper sheet bundle. The groove group 11 is directed to an outer periphery in one direction of the binding part 10 and the groove groups 12 and 13 orthogonal to the groove group 11 are each arranged so as to face an outer periphery in the other direction of the binding part 10.