To prevent such troubles that the trailing end parts of blank forms slipping down on a blank form placing table do not come into contact with the abutting surface of a paper trailing end abutting member, and the blank forms are irregularly arranged, then, the appearance of a bound book is deteriorated in the case of performing a binding processing and a folding processing.

As for the blank form post-processor constituted of a matching means for bringing the trailing end part of the blank form S placed on the blank form placing table 71 into contact with the abutting surface of the blank form trailing end abutting member 72 so as to position and align the blank form S, a binding means 700 for binding a part near the side edge part of the aligned blank form S or the center part of the blank form in the carrying direction, the post-processor is provided with a vibration means 79 for vibrating the blank form trailing end abutting member 72 in the blank form carrying direction, and a control means 200 for controlling the vibration timing of the vibration means 79.