An image forming device is disclosed that is able to superpose a smooth sheet on a toner image on a recording sheet after common thermal fusing, perform re-melting and solidification, and then separate the smooth sheet, thereby, forming a high-gloss image easily. The image forming device includes a first fusing unit for the common thermal fusing, and a second fusing unit for fusing the toner image on a recording sheet after the common thermal fusing with a gloss application sheet superposed on the toner image, and a separation unit for separating the gloss application sheet from the recording sheet. The gloss application sheet is superposed on the recording sheet with a side of the gloss application sheet projecting out beyond a side of the recording sheet on a downstream side in the conveyance direction, and the gloss application sheet and the recording sheet are directed into the separation unit while being superposed.