An electrochemical converter with proton membrane includes a plurality of electrochemical unitary cells connected in series and arranged on a carrier tape elongated along a longitudinal axis, a first face of which has anodes that receive hydrogen and a second face has cathodes that receive air, wherein the hydrogen circulates in a flow parallel to the longitudinal axis of the aforementioned tape and the air circulates in a flow transverse to the longitudinal axis of the aforementioned tape, and separation means dividing the air flow into a cooling flow having no contact with the cathodes and a cathodic reaction flow in contact with the cathodes.