NOVELTY - A membrane-electrode assembly comprises a cathode catalyst layer (14) for reducing an oxidant gas, a polymer electrolyte membrane (12), and an anode catalyst layer (13). The polymer electrolyte membrane is sandwiched between the catalyst layers. The cathode catalyst layer contains at least one of silicon compounds having perfluoropolyether chains, silicon compound having perfluoroalkyl chains or silicon compounds having fluoroalkyl chains.    USE - For use in fuel cell.    ADVANTAGE - The catalyst layer exhibits super-water-repellency, thus reaction water never adheres to the cathode catalyst layer so that the flooding phenomenon can be prevented completely (even at higher current density operation) and an output of the fuel cell can be increased.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) manufacturing an electrode-membrane assembly comprising irradiating oxygen plasma with surface of cathode catalyst layer supported on carbon, contacting the treated surface of with at least one fluorine-containing compound, and heating the treated catalyst layer;    (2) fuel cell comprising at least one unit cell, the electrode-membrane assembly, a pair of gas diffusion layers each in contact with the cathode catalyst layer and the anode catalyst layer, and a pair of separator each in contact with the gas diffusion layers;    (3) catalyst for fuel cell treated with at least one of silicon compounds having perfluoropolyether chains, silicon compound having perfluoroalkyl chains or silicon compounds having fluoroalkyl chains; and    (4) manufacturing a catalyst for fuel cell comprising irradiating a catalyst supported on carbon with oxygen plasma, contacting the treated catalyst with a silicon compound, and heating the treated catalyst.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross sectional view of a unit cell.    Separator (11)    Polymer electrolyte membrane (12)    Anode catalyst layer (13)    Cathode catalyst layer (14)    Gas diffusion layer (15)    Gasket (16)