NOVELTY - A membrane electrode assembly (12) consists of a polymer electrolyte membrane (1), electrode catalyst layers (2,3), and gas-diffusion layers (4,5). The electrode catalyst layer consists of carbon support, catalyst substance, and polymer electrolyte. The content of electrolyte in catalyst layer reduces towards the side contacting gas-diffusion layer when compared with the side contacting electrolyte membrane. The content of catalyst increases towards the side contacting gas-diffusion layer when compared with the side contacting electrolyte membrane.    USE - Membrane electrode assembly is used in polymer electrolyte fuel cells (claimed) used for vehicles and domestic applications.    ADVANTAGE - The membrane electrode assembly provides polymer electrolyte fuel cells having excellent output performance characteristics. The usage amount of catalyst substance is reduced as the catalyst substance of gas-diffusion-layer side is utilized effectively.    DETAILED DESCRIPTION - A membrane electrode assembly consists of a polymer electrolyte membrane clamped between a pair of electrode catalyst layers which are clamped by a pair of gas-diffusion layers. The electrode catalyst layer consists of a carbon support which supports a catalyst substance and a polymer electrolyte. The content of polymer electrolyte in the electrode catalyst layer reduces towards the side contacting gas-diffusion layer when compared with the side contacting electrolyte membrane. The content of catalyst substance in the electrode catalyst layer increases towards the side contacting gas-diffusion layer when compared with the side contacting electrolyte membrane. An INDEPENDENT CLAIM is included for polymer electrolyte fuel cell.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic disassembled view of the polymer electrolyte fuel cell.    Polymer electrolyte membrane (1)    Electrode catalyst layers (2,3)    Gas-diffusion layers (4,5)    Membrane electrode assembly (12)    Polymer electrolyte fuel cell (13)