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.