PURPOSE: To allow a liq. chemical feeding path to communicate selectively with a cathode or anode chamber by forming a first diaphragm fastening part at the tip side of a diaphragm supporting member and a second diaphragm fastening part at the rear side.

CONSTITUTION: Raw water introduced from a water feeding member 2 is sent to electrode chambers 9a, 9b in an electrolytic cell 1 and electrolyzed together with liq. chemicals for electrolysis under voltage impressed between electrodes 4, 5. By this electrolysis, alkaline ionized water and acidic ionized water are produced and separately discharged from a pair of water discharging holes 12a, 12b of a water discharging member 3. Upper and lower diaphragm supporting members 6, 7 are arranged with the tip sides opposite to each other so that tip ribs 18 forming water paths are brought into contact with the top and bottom of the inner electrode. The member 7 at the liq. chemical feeding hole 11 side has a liq. chemical path 17 in the thick part. Operation is carried out so as to produce alkaline water or acidic water.