PURPOSE: To protect water resource by storing bath water after bath in a tank, and using this water as the wash water of a toilet or car wash water by a feed water pump.

CONSTITUTION: A circulating pump 44 with purifying function is provided in a tank 41 so as to feed water in a bathtub 11 into the tank 41 through a drain pipe 43 while feeding water in the tank 41 to the bathtub 11 through a feed water pipe 42. A feed water pump 46 with purifying function is connected to the outside of the tank 41, and the water in the tank 41 can be discharged from plural discharge ports 47. One discharge port 47, for instance, is connected to the feed water tank of a toilet through piping, and the other discharge port 47 is connected to a hose disposed on the ground. At the time of taking a bath, the water in the bathtub 11 is purified and fed into the tank 41 by the circulating pump 44 and circulated to the bathtub 11 after being heated by a boiler 45 in the tank 41. After the bath, the water in the bathtub 11 is fed into the tank 41 and stored therein, and after being purified, suitably used for sprinkling on plants, car washing, and the like.