To efficiently wash an object, on which water is sprinkled, by a normal clean water pressure without providing a pressurizing pump, and to improve diffusivity and flowability of clean water on a surface of the object, on which water is sprinkled, and also to reduce the consumption of the clean water.

The clean water for sprinkling of water, which is generated by turning the clean water supplied from a clean water pipe (1) to microbubbles or nanobubbles by a bubble generation means (5), is sprinkled on the object, on which water is sprinkled.