An alkali metal chloride-electrolyzing cell comprises a cation-exchange membrane disposed between an anode and a cathode, characterized in that said cation-exchange membrane has on at least one side thereof a gas- and liquid-permeable, porous layer with no electrode activity, and at least one of an anode and a cathode is a voided flexible electrode having a more rigidity than that of said cation-exchange membrane, and said flexible electrode is designed to be forcibly deformed thereby closely contacting said cation-exchange membrane with the surface of each of said electrodes.