To facilitate the control of a differential pressure acting on a solid polymer electrolytic membrane in a water electrolytic cell using the membrane and to prevent the damage of the membrane.
This solid polymer membrane-type water electrolyzer is provided with a water electrolytic cell 1 divided by a solid polymer electrolytic membrane 3 into an anode chamber 1b and a cathode chamber 1a, a circulating line on the cathode-chamber side connected to the cathode chamber 1a and provided with a hydrogen-water separator 11 and a twin-shaft pump 41, a circulating line on the anode-chamber side connected to the anode chamber 1b and provided with an oxygen-water separator 25 and the twin-shaft pump 41 and an autonomous differential pressure control means 60 connected to both circulating lines and keeping the differential pressure between both constant.
TAKEDA HIROYUKI
NAKAMORI NOBUO
