The controller controls the folded bundle conveying portion such that, when a length in the conveying direction of the succeeding folded bundle makes the upstream edge in the conveying direction of the succeeding folded bundle, which is temporarily stopped for the folded end portion processing, remain within a stacking region of the sheet stacking portion, before the preceding folded bundle has been finally moved to the second stacking position, the succeeding folded bundle is conveyed until the upstream edge in the conveying direction of the succeeding folded bundle, to which the folded end portion processing has been applied, passes through outside the stacking region of the sheet stacking portion.