A post-fixing support unit which is disposed between a fixing roller including a heating roller having a heat generator and a pressure roller so disposed opposite to the heating roller as to form a nip portion and a plurality of sheet discharge rollers which are disposed on the downstream side relative to the fixing roller and corrugation rollers disposed respectively between the adjacent two sheet discharge rollers, such that the post-fixing support unit is located on the upstream side relative to the corrugation rollers at the same position as at least the corrugation rollers in the width direction.