To sophisticate the control of a stapling operation and to avoid the change of the structure of a stapler with regard to a stapler driver etc.

A stapler driving method includes a first procedure for detecting an electric current flowing in a DC motor which is the driving source of the stapling operation, a second procedure for specifying the point of time of the end of a binding process when the stapling operation is divided into a starting process for starting power supply to the DC motor when the stapler implementing the stapling operation is in an initial state, the binding process in which a staple needle is inserted into a bundle made of a plurality of overlapped recording medium sheets to bend the needle, and a return process for returning the bundle to an initial state after binding it based on the electric current detected in the first procedure, and a third procedure for changing power supplied to the DC motor when the stapling operation is implemented at the time specified in the second procedure.