According to the present invention an exothermic member is provided freely rotatably and formed in a ring form composed of an exothermic resistor layer of high resistivity formed on an inner peripheral surface and a conductor layer of low resistivity formed on the outer peripheral surface of the exothermic resistor layer. A medium-leading member is provided for forming a conveyance path for media with the outer peripheral surface of the exothermic member in between and a pressing electrode member is provided for supporting the exothermic member in abutting against the exothermic resistor layer in a conductive state in a position opposing to the medium-leading member. A power supplying electrode is also provided being connected to the conductor layer making contact at least with a brim part on one side of the exothermic member and voltage is applied between the exothermic member and the pressing electrode member by a power supply and only a part of the exothermic member against which the pressing electrode member is abutting generates heat. Such a structure allows for fixing an image to be transcribed consisting essentially of toner formed on a recording medium when it passes through this part of the conveyance path.