PROBLEM TO BE SOLVED: To provide a system in which oxidation-reduction potential value is minus and active oxygen is eliminated or is suppressed, and to provide its utilizing method in purification of water by discharge at high voltage. SOLUTION: Water in a water bath in which a zealite type quartz diorite named Ioseki in Japanese is immersed for 7 to 30 days is dropped down into a next water bath at high speed by applying water pressure in order to obtain water having minus oxidation-reduction potential value and preservable for a long period by making water molecules smaller, making water contain minus ions and rich in minerals and applying high voltage. Then the water is poured into a water bath made of an insulating material in which high voltage is newly applied to discharge and a plurality of projection shapes with points top end parts are provided at a cathode side and an anode side where high voltage is discharged in order to heighten discharging effect. Further at this time, the zeolite type quartz diorite is immersed in this bath and is respectively connected with the cathode and the anode and the cathode and the anode are not directly connected with each other.
