NOVELTY - The membrane electrode assembly has solid polymer electrolyte membrane (1) provided between anode (5) and cathode (6). Catalyst layer of anode and cathode contains carbon particles (optionally supporting catalyst component) having preset properties and fluorine-type electrolyte resin and has porosity of 60-80% and thickness of 5-20 microns. The gaseous diffusion restriction layer of anode and cathode contains carbon particles and fluorine resin. The gas diffusion property of the gaseous diffusion restriction layer of the anode and cathode is smaller than the catalyst layer.    USE - Membrane electrode assembly for fuel cells used as power supply for motor vehicles.    ADVANTAGE - The membrane electrode assembly has favorable electric power generation efficiency.    DETAILED DESCRIPTION - The membrane electrode assembly has solid polymer electrolyte membrane provided between anode and cathode. The anode (5) has lamination of anode side catalyst layer (2a), anode side gaseous diffusion restriction layer (4a) and anode side gaseous diffusion layer (3a). The cathode (6) has lamination of cathode side catalyst layer (2b), cathode side gaseous diffusion restriction layer and cathode side gas diffusion layer (3b). The catalyst layer contains carbon particles (optionally supporting catalyst component) and fluorine-type electrolyte resin, in a weight ratio of 0.8:1-2:1, and has porosity of 60-80% and thickness of 5-20 microns. The carbon particles have particle size of 10-40 nm and specific surface area of 400-1000 m2/g. The anode side gaseous diffusion restriction layer contains carbon particles having specific surface area of 0.5-1000 m2/g and fluorine resin in a weight ratio of 0.8:1-20:1. The gas diffusion property of each layer is represented by formula: porosity/asterisk(1/thickness). The gas diffusion property of the anode side gaseous diffusion restriction layer is smaller than the catalyst layer.    DESCRIPTION OF DRAWING(S) - The drawing shows the top view of the membrane electrode assembly.    Solid polymer electrolyte membrane (1)    Anode side catalyst layer (2a)    Cathode side catalyst layer (2b)    Anode side gaseous diffusion layer (3a)    Cathode side diffusion layer (3b)    Anode side gaseous diffusion restriction layer (4a)    Anode (5)    Cathode (6)    Membrane electrode assembly (10a)