To convey a following sheet toward a discharge tray together with a preceding sheet made to wait in a buffer path, while a switch member provided at a branch portion of the path is maintained at a lower position, the following sheet conveyed from an upstream side of the branch portion toward the discharge tray is guided by a second guide face of the switch member at the lower position, made to meet the waiting sheet on a downstream side of the switch member, and conveyed toward the discharge tray in a sheet bundle.