A process for manufacturing a gas diffusion electrode comprising an electrochemically active layer, a water-repellent layer and an integrated current collector, said process comprising the steps of: (i) preparing said electrochemically active layer comprising an electrically conductive powder and a first binder; (ii) preparing a second layer comprising a pore-forming agent and particles of a hydrophobic material and/or a second binder on said electrochemically active layer to provide a laminate; (iii) assembling said electrochemically active layer, said second layer and said current collector such that said electrochemically active layer is sandwiched between said current collector and said second layer; and (iv) rendering said second layer water repellent by realising porosity therein, thereby providing said gas diffusion electrode; a gas diffusion electrode obtainable by said process; a membrane assembly comprising at least one of said gas diffusion electrodes; a method of manufacturing a membrane assembly comprising said membrane sandwiched between two electrodes at least one of which is said gas diffusion electrode, wherein said method comprises: the step of casting said membrane electrode assembly in two steps; the use of said gas diffusion electrode in any cell operating in galvanic or electrolytic mode; and a process for manufacturing a water repellent layer of said gas diffusion electrode, said process comprising the steps of: (a) mixing a pore forming agent with particles of a hydrophobic material and/or a second binder to form a second mixture; (b) pressing the second mixture into a homogeneous cake; and (c) reducing the cake in thickness by at least two passes through a calendaring machine to produce the second layer on the electrochemically active layer.