To make control of a stapling action according to an image forming apparatus.

A post-processing device includes: a bundle forming section for receiving recording mediums from the image forming apparatus for forming the image on the recording mediums and forming a bundle by layering a plurality of sheets of those recording mediums; a stapler with a motor inserting the staples into the bundle and bending by the driving force of the rotation of the motor and executing the stapling action which is one type of post-processing; a power supplying section for supplying power to the motor in the stapler; a power storage section for storing the power that is notified from the image forming apparatus; and a power control section for making the power supplying section supply the power stored in the power storage section toward the motor.