PURPOSE: To make the electrolytic power source in an ionized water generator efficient and to conduct overcurrent protection.

CONSTITUTION: A constant-voltage power source is turned on to change the resistance of potentiometric resistor R11 by ladder resistors R12, ...R15 and a flow rate resistor R16 with the signal of a CPU 7, and the electrolytic level of an output voltage is made variable. The overcurrent protection threshold value of an overcurrent comparator 6 is simultaneously set in linking with each other by the ladder resistors R20, ...R25, flow rate resistor R26, etc. Either the detected voltage obtained by converting the detected current of a CT 2 by voltage conversion circuits 3, 4 and 5 or the voltage of the R2 terminal of an electrolytic power source ON/OFF transistor Q2 is inputted and compared by the comparator, and, when the current is over, an electrolysis stop signal is outputted from the CPU to conduct PWM and duty ratio control.