This invention provides a solid polymer ion exchange membrane/electrode assembly, or an electrode/solid polymer ion exchange membrane/electrode assembly, for an electrochemical cell, which consists of planar layers of materials intimately joined together to form a unitary structure. The layers are joined together by solid polymer ion exchange resin present in at least one of each pair of adjacent layers. The unitary assembly can be used in an electrochemical cell such as a battery, electrolytic reactor, or fuel cell.