PURPOSE: To reduce the odor of human waste by a method in which a person in the toilet is detected by a sensor and during the period when the person is in the toilet, water is allowed to flow intermittently for a preset time period.

CONSTITUTION: When a person is in a toilet, the person is detected by a sensor 41, and a relay switch 42 is operated by a sensor circuit 4 according to detected signals. The detected signals are sent to CPU circuit 3. After 3 seconds from time when the CPU circuit 3 receives the detected signals, a solenoid valve 51 is opened for 1W5 seconds, for example, to allow water of about 2 liters to flow to a conduit 51a. At the same time, an ozonizer unit 52 and a ventilation device 53 begin to work. After 60 seconds, the solenoid valve 51 is opened for 1W5 seconds to cause water of about 3 liters to flow. When the person comes out of the toilet, the valve 51 is opened for 1W10 seconds three minutes thereafter to cause water of about 7 liters to flow, and the unit 52 and the device 53 are stopped. Maloperation can be prevented by time lag of each 3 seconds.