NOVELTY - Manufacture of metal gas-diffusion layer involves forming (DD) an electroconductive layer including a carbon film layer on a metal porous component, and forming (HH) a water-repellent layer on the metal porous component in which the electroconductive layer is formed. The water-repellent layer is formed by coating a solution containing fluororesin on the metal porous component, and heat-processing (JJ) at temperature less than the destructive temperature of electroconductive layer and more than the evaporation temperature of volatile component contained in the solution.    USE - Manufacture of metal gas-diffusion layer (claimed) used for fuel cell for vehicle.    ADVANTAGE - The method enables economical manufacture of metal gas-diffusion layer with excellent electroconductivity and water-repellent property. Since the heat-processing temperature is less than the destructive temperature of electroconductive layer during formation of water-repellent layer, the destruction of the electroconductive layer is suppressed.    DETAILED DESCRIPTION - Manufacture of metal gas-diffusion layer involves forming an electroconductive layer including a carbon film layer on a metal porous component, and forming a water-repellent layer on the metal porous component in which the electroconductive layer is formed. The water-repellent layer is formed by coating a solution containing fluororesin which forms water-repellent layer on the metal porous component, heat-processing at temperature less than the destructive temperature of electroconductive layer and more than the evaporation temperature of volatile component which does not form water-repellent layer and contained in the solution, and forming the water-repellent layer comprising fluororesin. The metal gas-diffusion layer is used for fuel cell which consists of metal porous component arranged between a polymer electrolyte membrane and a separator.    DESCRIPTION OF DRAWING(S) - The drawing shows a flowchart explaining manufacture of the metal gas-diffusion layer. (Drawing includes non-English language text)    Formation of electroconductive layer (DD)    Removal of oxide film (EE)    Formation of intermediate layer (FF)    Formation of water-repellent layer (HH)    Heat-processing (JJ)