PURPOSE: To prevent the corrosion of an electrode or the deformation of an electrolytic cell when the electrolytic cell is heated by any abnormality by providing an electrolysis control means controlling electrolytic treatment so as to stop the same when detected temp. exceeds a preset value.

CONSTITUTION: The constant voltage power supply 12 of the power supply circuit 14 constituting an electrolysis control means is turned ON when the flow rate detected by a flow rate sensor in such a state that a main power supply switch 16 is closed is, for example, 2L/min or more and turned OFF when the detected flow rate is 2L/min or less. When the detected temp. from the temp. sensor 10 detecting the surface temp. of an electrolytic cell 8 is a preset value, for example, 50°C or higher during electrolysis, the power supply is turned OFF and, at this time, an LED 18 informing that there is abnormality in a water conditioning machine lights. So far as the power supply circuit 14 is not reset by once opening the main power supply switch 16, the constant voltage power supply 12 is not again turned ON.