Membrane-electrode assemblies are provided which have polymer electrolyte membranes capable of maintaining an adequately wet condition even at high temperatures and have superior generating properties. The membrane-electrode assembly includes an ion exchange resin membrane, an anode catalyst layer including catalyst-supported carbon and an ion exchange resin, and a cathode catalyst layer including catalyst-supported carbon and an ion exchange resin, the anode catalyst layer including a binder component of which the ion exchange capacity is higher than that of a binder component in the cathode catalyst layer, and/or the anode catalyst layer including an ion exchange resin layer of which the water content is higher than that of anion exchange resin layer of the cathode catalyst layer.