The purpose of the present invention is to provide a sheet bundle binding processing apparatus capable of performing a binding process on a sheet bundle set at a manual setting portion and a sheet bundle set on a processing tray, respectively, with a simple structure at low cost. The present invention comprises a sheet bundle binding processing apparatus including an external casing, a manual setting portion which is integrally formed with the external casing and to which a sheet bundle is inserted, a binding device which performs a staple-binding process on the sheet bundle inserted to the manual setting portion as being movable between a binding position where the sheet bundle of the manual setting portion is bound and a staple replenishment position where staples are replenished, and an open-close cover which is arranged at the external casing at a position being different from the manual setting portion.