A method for manufacturing a membrane-electrode assembly for a fuel cell comprises the following steps: a first step during which a reinforcement (2) is deposited on a first face of an ion-exchanging membrane (1), the membrane being held on a support film; a second step during which the membrane is unglued from the support film; a third step during which the reinforcement (2′) is deposited on the second face of the ion-exchanging membrane; and a fourth step during which a chemical catalyst element is deposited on the parts left free of the first and second faces of the membrane.