NOVELTY - The heater (1) has a fuel supply chamber (4) into which fuel gas is supplied and a catalyst chamber (5) into which oxidizing gas is supplied. The fuel supply chamber and catalyst chamber are separated by a fuel gas permeable film (2), so that fuel gas is supplied from the fuel supply chamber to the catalyst chamber through the permeable film.    USE - Sheet type catalyst heater for fuel cell used in motor vehicle (both claimed).    ADVANTAGE - The size of the catalyst heater is reduced and distribution of heat in the heater is performed uniformly by using a simple arrangement.    DETAILED DESCRIPTION - The heater has a permeable film (7) formed between oxidizing gas supply chamber (6) and catalyst chamber, so that oxidizing gas is supplied from the oxidizing gas supply chamber to the catalyst chamber through the permeable film. A fuel supply chamber and catalyst chamber are separated by a fuel gas permeable film, so that fuel gas is supplied from the fuel supply chamber to the catalyst chamber through the permeable film. A catalyst is coated with a carrier formed in the shape of rod or fibrous material. The thickness of the fuel gas permeable film is in the range of 0.01-5.0 mm and gas permeability of the fuel gas permeable film is in the range of 0.1-100x 10-9 cm3x cm/secx cm2x cm Hg. A spacer is formed inside the fuel supply chamber, for introducing fuel gas into the chamber. A heat insulating material is formed inside the oxidizing gas supply chamber. A fuel gas impermeable film (3) and oxidizing gas impermeable film (8) are formed on the outer surface of the fuel supply chamber and catalyst chamber. The catalyst chamber is arranged on both sides of the fuel supply chamber and made to contact with the fuel gas permeable film.    DESCRIPTION OF DRAWING(S) - The drawings show the perspective view and sectional view of the catalyst heater and explanatory view of the rod-shaped carrier.    Sheet-type catalyst heater (1)    Fuel gas permeable film (2)    Fuel gas impermeable film (3)    Fuel supply chamber (4)    Catalyst chamber (5)    Oxidizing gas supply chamber (6)    Oxidizing gas permeable film (7)    Oxidizing gas impermeable film (8)    Catalyst structure (9)