An active layer/membrane assembly to be incorporated into a hydrogen production device comprises an active layer in contact with a membrane capable of exchanging ions, the active layer comprising catalyst particles and particles referred to as support particles, wherein the size of the support particles is greater than the thickness of the active layer, so that the support particles emerge from the active layer, at the surface opposite the surface in contact with the membrane. A unit comprising the assembly and a porous current collector, the assembly and the collector having a complementarity of surface finish is provided. A process for manufacturing the assembly is also provided.