Abstract: The membrane electrolyzer comprises parts which have been provided for or used in a diaphragm electrolyzer. within a single frame of the membrane electrolyzer are contained from one to three anodes, which have been provided for or used in a diaphragm electrolyzer. Each anode has electrochemically active anode surfaces having a grid structure and a current conductor, which is disposed between the anode surfaces and connected to the frame. The current conductors of the anodes preferably extend through the frame and are connected to a current-carrying bar or plate.