CONTROL METHOD OF VACUUM WASHING TOILET BOWL

PROBLEM TO BE SOLVED: To provide a control method by which noise generated when a water drain valve is closed is reduced markedly. SOLUTION: When a wash switch 17 is pressed, a water supply valve 13 and a water drain valve 4 are opened to supply wash water to a bowl 11, and contents in the bowl 11 are discharged into a vacuum pipe 5. When time t1 elapses after the valves 13, 4 are opened, the water supply valve 13 is closed, and when time t2 elapses after the water supply valve 13 is closed, the water drain valve 4 is closed. Furthermore, when time t3 elapses after that, the water supply valve 13 is opened. When time t4 elapses, the water supply valve 13 is closed, and water is collected in the bowl 11.