Abstract: A sheet processing apparatus includes a binding unit including a binder which binds a predetermined number of gathered sheets by striking one or more staples into the sheets, a cutter which cuts off staple feet in accordance with a thickness of the sheets after the staples are struck, and a first housing which receives staple waste of the cut staple feet. The apparatus also includes a second housing which receives the staple waste from the first housing at a designated timing. The first housing has an openable cover which shifts from a closed state to an open state when the staple waste is transferred from the first housing to the second housing. A deformable member having an elastically deformable surface is provided on at lea a rim of an internal surface of the openable cover.