NOVELTY - A membrane electrode assembly (50) has electrolyte membrane (20), cathode catalyst layer (30) formed in one surface of electrolytic membrane, and anode catalyst layer (26) formed in one surface of electrolytic membrane. Cathode catalyst layer and/or anode catalyst layer contain platinum-containing catalyst, electroconductive carrier particles which support the catalyst metal, silica component which covers at least one portion around catalyst metal and carrier particles, and ionomer having proton conductivity. Catalyst layer has volume resistivity of 1-100 ( Omega ).cm.    USE - Membrane electrode assembly is used for fuel cell (claimed) e.g. polymer electrolyte fuel cell.    ADVANTAGE - The fuel cell using membrane electrode assembly has excellent electric power generation performance.    DETAILED DESCRIPTION - A membrane electrode assembly has an electrolyte membrane, a cathode catalyst layer formed in one surface of the electrolytic membrane, and an anode catalyst layer formed in one surface of the electrolytic membrane. The cathode catalyst layer and/or anode catalyst layer contain platinum-containing catalyst, electroconductive carrier particles which support the catalyst metal, silica component which covers at least one portion around the catalyst metal and carrier particles, and an ionomer having proton conductivity. The content of silica component is 1-15 %mass with respect to total content of catalyst metal in catalyst layer, carrier particles and silica component. The catalyst layer has volume resistivity of 1-100 ( Omega ).cm. An INDEPENDENT CLAIM is included for fuel cell (10), which has membrane electrode assembly, cathode side separator and anode side separator.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of fuel cell.    Fuel cell (10)    Electrolyte membrane (20)    Anode (22)    Cathode (24)    Anode catalyst layer (26)    Anode gas diffusion layer (28)    Cathode catalyst layer (30)    Membrane electrode assembly (50)