Post-processing device

A post-processing device comprising:

• a stacking section that aligns and stacks recording materials which are sequentially transported;
• a saddle stitching section that binds a plurality of sheets of recording materials, which are stacked on the stacking section, in central portions of the recording materials;
• a center folding section that folds the plurality of sheets of recording materials, which are bound in the central portions by the saddle stitching section, into two in the central portions;
• a pressing section that presses a booklet, which is formed of the plurality of sheets of recording materials center-folded by the center folding section, in a thickness direction of the booklet;
• and
• a discharge section that discharges the booklet, which is pressed by the pressing section, with a folded portion of the booklet being a leading edge;
• wherein the post-processing device is configured to be controlled by a controller such that the booklet is held and stopped in a state of being nipped by the discharge section, such that a portion of the booklet including the leading edge protrudes from the discharge section in the direction of discharge, such that the lending edge hangs free, and transport is initiated after the lapse of a predetermined stop time so that the booklet is discharged.