The present invention provides a sheet processing apparatus that can
prevent, with higher certainty, lift of the trailing end of each sheet
placed in sheet stacking portion. This apparatus includes a first holding
member and a second holding member that prevent lift of the trailing end
of each sheet from an intermediate stacking portion. When introduced to
the intermediate stacking portion, the subsequent sheet comes into
contact with the first holding member, so that the first holding member
moves to the retracting position. As the subsequent sheet continues to be
conveyed, the subsequent sheet comes into contact with the second holding
member, so that the second holding member moves from the restricting
position to the retracting position. As the trailing end of the sheet is
introduced, the first holding member moves from the retracting position
to the restricting position, to hold down the trailing end of the sheet.