NOVELTY - A membrane-electrode assembly has an anode catalyst layer (14a), a cathode catalyst layer (14b), and a polymer electrolyte membrane (12) provided between the anode and cathode catalyst layers. The polymer electrolyte membrane contains hydrocarbon-type polymer electrolyte having an ion-exchange group. The anode and cathode catalyst layers contain a catalyst, and hydrocarbon-type polymer electrolyte having ion-exchange group. The ion-exchange group density ( alpha ) (in ( mu m)eq/cm2) of anode catalyst layer is less than 0.45.    USE - Membrane-electrode assembly is used for polymer electrolyte fuel cell (claimed) used as electrical power source in motor vehicle.    ADVANTAGE - The membrane-electrode assembly provides polymer electrolyte fuel cell with improved power generation property.    DETAILED DESCRIPTION - A membrane-electrode assembly has an anode catalyst layer, a cathode catalyst layer, and a polymer electrolyte membrane provided between the anode and cathode catalyst layers. The polymer electrolyte membrane contains hydrocarbon-type polymer electrolyte having an ion-exchange group. The anode and cathode catalyst layers contain a catalyst, and hydrocarbon-type polymer electrolyte having ion-exchange group. The ion-exchange group density ( alpha ) (in ( mu m)eq/cm2) of anode catalyst layer is less than 0.45, and the ion-exchange group density ( beta ) (in ( mu m)eq/cm2) of cathode catalyst layer is less than 0.85 or less. The ratio of ion-exchange group density ( beta ) to the ion-exchange group density ( alpha ) is greater than 1. The anode catalyst layer and/or cathode catalyst layer are formed using ink composition containing solvent (a) chosen from water and hydrophilic substance, catalyst substance (b) and hydrocarbon-type polymer electrolyte (c). An INDEPENDENT CLAIM is included for manufacture of the membrane-electrode assembly.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the fuel cell.    Fuel cell (10)    Polymer electrolyte membrane (12)    Anode catalyst layer (14a)    Cathode catalyst layer (14b)    Gas diffusion layers (16a,16b)    Separators (18a,18b)