WASHING SYSTEM FOR URINAL

PROBLEM TO BE SOLVED: To detect the presence of urination by a pressure sensor, to causes operation of a washing system even when a status is low like a child, to prevent the occurrence of malfunction due to spreading of a hand like an infrared ray sensor, and to prevent the damage of a pressure sensor. SOLUTION: A washing system for an urinal comprises a trap part 5 arranged at the bottom of an urinal body 1 and temporarily storing a given amount of liquid; a washing water piping 7 to feed washing water to the urinal body 1; and a flow rate regulating valve 8 arranged in the washing water piping 7. In this case, the washing system is provided with a pressure sensor 10 to detect the change of a liquid level in the trap part 5, and a control means to regulate the opening of the flow rate regulation valve 8 according to the change of a liquid level in the trap part 5 detected by the pressure sensor 10. The pressure sensor 10 is arranged at the side of the trap part 5 and a pressure introduction pipe 13a of the pressure sensor 10 is opened directly to the trap part 5.