An image forming device for adequately forming an image in which images overlap one another. The priority order (display order) of the images overlapping with one another is judged for the area where images of different attributes overlap with one another. When the priority rank of a three-dimensional image is high, a planar image in the overlapping area is deleted, or a three-dimensional image is formed on a planar image. When the rank of a planar image is high, only the color image of a three-dimensional image in the overlapping area is deleted, and a planar image is formed using foaming toner.