Sheet processing apparatus and image forming apparatus

A sheet processing apparatus comprising:

• an intermediate stacking portion for aligning a sheet sent;
• a reference wall, disposed on one side in a width direction intersecting a conveying direction of the sheet, for serving as a reference for positioning the sheet;
• a stapler for performing a binding operation on one side in the width direction of the sheet with respect to a sheet bundle aligned by the reference wall;
• delivery means for delivering the sheet bundle from the intermediate stacking portion;
• a sheet stacking portion for stacking the sheet bundle delivered from the delivery means;
• and
• guide means provided above the sheet stacking portion and at an end portion on the stapler side of the end portions in the width direction of the sheet,
• wherein the guide means supports an end portion on the stapler side of the sheet bundle when the sheet bundle is delivered from the delivery means in a staple mode in which the binding operation is performed with respect to the sheet bundled.