A sheet discharge unit of an image forming apparatus includes a first path discharging the sheet to the outside, a second path for feeding the sheet again to the image forming unit in the case of performing a duplex image forming process, a sheet conveyor conveying the sheet from the first path to the outside, and a corrugating member corrugating the sheet in a width direction of the sheet orthogonal to a conveying direction of the sheet to give the sheet stiffness when the sheet conveyor conveys the sheet. The second path includes an upstream path section having a width that extends in a thickness direction of the sheet, the width being set to be narrow to such a degree that the corrugation of the sheet is reduced when the sheet passes the upstream path section.