PURPOSE: To obtain sterilization and disinfection functions by producing acid water and alkali-ionic water by electrolysis applied in an electrolizer, and by utilizing warmed acid water for warm-water cleaning of private parts while utilizing the alkali-ionic water for flushing.

CONSTITUTION: Acid water and alkali-ionic water are produced by electrolysis out of running water supplied to an electrolizer 2, and the acid water is supplied to a cleaning warm water tank 8 through a valve 7. Warmed acid water is led through a pump 9 to a nozzle 11 provided to a heated toilet seat 10 and is used for warm-water cleaning of private parts and after the cleaning, the acid water is allowed to flow out of a toilet bowl 12 into a purifying tank. Running water and alkali-ionic water stored in a wash-water tank 4 is used, together with washing water, for flushing of the toilet bowl 12 and is allowed to flow into the purifying tank. Thereby sterilization and disinfection can be executed at the same time with the warm-water cleaning.