In an induction heat fixing device of the invention, a metal conductive layer of a heat roller is supported by a foamed rubber (sponge). A sheet paper is curled in a direction of separating from the heat roller by a nip shape between the heat roller and a press roller. The press roller is formed to be longer than the heat roller to such a degree that even if the heat roller laterally shifts, an edge of the press roller does not come in contact with the heat roller.