Abstract: A filter press electrolyzer, such as for use in a chlor-alkali cell, has electrode assemblies which include a pan-shaped structure. The pan members have a planar floor and an upright side around the peripheral edge of the floor. The upright side terminates upwardly in a rim. The pan members are elongate, thereby providing long, at least substantially parallel sides at long pan edges as well as short sides at the top and bottom of the pan. On the pan floor are a series of parallel, rigid stand-offs, which project upwardly from the floor. These hold electrodes away from the back of the pan. These electrodes are typically large, somewhat flexible and at least substantially planar members, usually made of metal mesh. The stand-offs can include principal stand-offs located at the central area of the pan, plus additional stand-offs, typically one each at the top and bottom of the pan.