A separation device 16, which is located downstream from a transfer roller in the sheet transport direction, applies a separation voltage to a plurality of separation needles 17 disposed in an alignment orthogonal to the direction of transport of the sheet, so as to produce a discharge between a photosensitive drum 2 and the separation needles 17 and to remove the charge on the sheet that was charged by a transfer roller, so as to separate the sheet from the photosensitive drum 2, the separation device 16 having an upstream wall 27 and a downstream wall 28, and a ground electrode 33 being disposed on the back side of the downstream wall 28, which is the side not facing the separation needles 17, and protruding towards the photosensitive drum 2, beyond the line that connects the tips of the separation needles 17 and the end of the downstream wall 28.