NOVELTY - A polymer electrolyte cell (C1) and membrane electrode assembly with water holding layer comprises anode and cathode diffusion layers and catalytic layers; and polymer electrolyte membrane. The cathode catalytic layer comprises a catalyst in which platinum or its alloy is supported on carbon supporting body (I). A water holding layer is arranged at an interface of the cathode diffusion layer and the cathode catalytic layer.    USE - As an electrolyte fuel cell (claimed).    ADVANTAGE - The polymer electrolyte cell containing several units possesses superior power generation efficiency under high voltage operation, particularly under low humidity operation. Due to the water holding layer, water generated by the reaction is held in this water holding layer. Therefore, when water is in short supply in the catalytic layer under low humidity operation, water is supplied from the water holding layer, and as a result, increasing of activation over voltage can be restrained. Since a heat treatment is performed on the catalyst supporting body to obtain the graphitized support catalyst, properties against electric potential corrosion are improved. Therefore, decomposition of the catalytic layer and elution of sulfonic acid groups and fluorinated acid groups from the electrolyte can be restrained even under high voltage operation, and as a result, efficiency deterioration of membrane electrode assembly (MEA) can be restrained.    DETAILED DESCRIPTION - A polymer electrolyte cell (C1) comprises an anode site separator, an anode diffusion layer, an anode catalytic layer, polymer electrolyte membrane, a cathode catalytic layer, a cathode diffusion layer, and a cathode side separator. The cathode catalytic layer comprises a catalyst in which platinum or platinum alloy is supported on a carbon supporting body having an average lattice space d002 of (002) surface of 0.338 - 0.355 nm and specific surface area of the supporting body of 80 - 250 m2/g; electrolyte containing ion exchange resin; and vapor grown carbon fiber. A water holding layer containing ion exchange resin, carbon particles, and vapor grown carbon fiber is arranged at an interface of the cathode diffusion layer and the cathode catalytic layer.