MANUFACTURING METHOD OF PURE WATER AND DEVICE FOR MANUFACTURING PURE WATER

PROBLEM TO BE SOLVED: To enhance the recovery percentage of treated water excellent in water quality of the treated water and to produce pure water easily and at a low cost with a simple equipment. SOLUTION: A cathode room 2 having a cathode 1, and an anode room 4 having an anode 3, are arranged. A desalting room 7 and a concentration room 8 are alternately formed by a cation exchange membrane 5 and an anion exchange membrane 6 alternately arranged between the cathode room 2 and the anode room 4. A water pressure adjusting valve 20 of treated water for adjusting back-pressure of the treated water treated in the desalting room 7, and a pressure adjusting valve 21 of concentrated water for adjusting back- pressure of the concentrated water concentrated in the concentration room 8, and a pressure adjusting valve 22 of electrode water for adjusting back- pressure of the electrode water flowed out from the anode room 4 and the cathode room 2 are provided for the device. Thus, the treated water, the concentrated water and the electrolyzed water are prevented from permeating through the cation exchange membrane 5 and the anion exchange membrane 6.