SHEET POST-PROCESSING DEVICE, AND IMAGE FORMING DEVICE INCLUDING THE SAME

PROBLEM TO BE SOLVED: To provide a sheet post-processing device capable of efficiently lumping some stapled sheet bundles as a large group, and easily segmenting, as small groups, some sheet bundles lumped together as a large group.SOLUTION: This sheet post-processing device includes: a first stitching processing means to perform stitching processing to a sheet bundle formed into a bundle-like form; a first holding means to hold the sheet bundle so as not to move; a discharge means to discharge the sheet bundle loaded on a sheet loading means; and a second holding means to hold the sheet bundle discharged by the discharge means so as not to move; wherein a second stitching processing means to perform stitching processing again to the sheet bundle discharged by the discharge means is added, and an evacuation means to evacuate the sheet bundle after the second stitching processing is arranged.