A switch back path is connected to a sheet feed path through a branch portion. A plurality of pairs of forward and backward rotating rollers are disposed along the switch back path from the branch portion. A driving portion selectively supplies rotation of a forward rotation direction or of a backward rotation direction to a plurality of pairs of forward and backward rotating rollers. A separation mechanism separates a first pair of forward and backward rotating rollers from each other. A control portion controls operation of the driving portion and the separation mechanism so that a sheet to be fed into the switch back path and a sheet to be fed out of the switch back path pass each other in the switch back path.