TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compound: The inorganic layered compound is talc, fluorine mica, smectite, bentonite, hectorite and/or saponite. Preferred Method: The nanocomposite polymeric electrolyte film is obtained by applying nanocomposite polyelectrolyte to at least one surface of polymeric electrolyte film which does not contain an inorganic layered compound. Alternately, the film is formed by mixing polyelectrolyte and inorganic layered compound without using solvent and extruding the kneaded material in the form of a film. The fuel cell has gas diffusion layers (4,5) formed by coating solution of carbon supported with catalyst containing platinum and polyelectrolyte on both sides of electrolyte film.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: The inorganic layered compound is talc, fluorine mica, smectite, bentonite, hectorite and/or saponite. Preferred Method: The nanocomposite polymeric electrolyte film is obtained by applying nanocomposite polyelectrolyte to at least one surface of polymeric electrolyte film which does not contain an inorganic layered compound. Alternately, the film is formed by mixing polyelectrolyte and inorganic layered compound without using solvent and extruding the kneaded material in the form of a film. The fuel cell has gas diffusion layers (4,5) formed by coating solution of carbon supported with catalyst containing platinum and polyelectrolyte on both sides of electrolyte film.    TECHNOLOGY FOCUS - POLYMERS - Preferred Polymer: The polymeric principal chain of polyelectrolyte is fluorine type polymer or hydrocarbon type polymer. A proton acid group is contained in the polymeric side chain. EXAMPLE - 3 pts wt. Fluorine mica was mixed with 100 pts.wt. Nafion liquid to form polymeric electrolytic solution. The solution was coated on glass panel and air dried for 1 day and heated at 120degreesC for 5 minutes. The coated glass panel was immersed in water and nanocomposite polymeric electrolyte film was removed from the glass panel. The thickness of the electrolyte film was 55 microns. Nafion solution was added to carbon powder comprising platinum to form a slurry. The slurry was coated on both surfaces of nanocomposite polymeric electrolyte film and dried to form polymer film electrode. Similarly, gas diffusion layer was formed. A fuel cell comprising electrode and gas diffusion layer was formed. The hydrogen permeation coefficient of polymer film and gaseous diffusion layer was each 1.1x10-8 cm3.cm/cm2.second.cmHg.