A stack, to be used in a fuel cell or electrolyzer, includes a collector layer, at least one diffusion layer and at least one anchoring layer. The collector layer being a metal foil or metal plate or foamed metal sheet, the diffusion layer can be a metal mesh or expanded metal sheet. An anchoring layer having a thickness of less than 0.5 mm can include metal fibers and be sintered between the collector layer and the diffusion layer.