Abstract: In a heating-type toner-fixing unit using a ceramic heater and a cylindrical fixing film, the shape of the fixing face-side surface of a ceramic heater 10 which comes into contact with a fixing film 3 and the shape of the portions of a heater support 12 at least adjacent to the fixing face-side surface are formed into a shape that is almost identical to a naturally deformed shape of the fixing film 3 in a static state or a traveling state where the fixing film is pressed by a pressure roller 4 at a designated nip width. It is also possible that the nip portion and portions adjacent thereto at the entrance side and exit side are formed into a flat shape and portions other than the flat portions are formed into a curved surface shape along the cylindrical shape of the fixing film 3.