PURPOSE: To prevent the growth of a microorganism in a bathroom and to improve the sanitary environment in the bathroom by constituting the bathroom so that ozone having sterilizing power is exhausted from an exhaust port provided on the ceiling or the wall surface of the bath room, and oxygen enrichment air can be exhausted from the same exhaust port.

CONSTITUTION: Air A of the outside of a bathroom is converted to oxygen enrichment air AO by allowing it pass through an oxygen enrichment device 1, and thereafter, also supplied to an ozone generating device 2, ozone O is added to the oxygen enrichment air AO, exhausted from an exhaust port 7 provided on the ceiling 5 or the wall surface 6 through a feed air pipe 5, and the inside of the bathroom 4 is sterilized and purified. Also, usually, an operation of the ozone generating device 2 is stopped selectively and it is used, and only the oxygen enrichment air is supplied to the bathroom 4, therefore, an agreeable bathroom space is held. Moreover, on the surface of the bathroom 4, an ozone sensor 8 and a human body detecting sensor 9 are provided, and in the case concentration of ozone in the bathroom 4 exceeds 1PPM in the course of sterilization and purification, and when a person tries to go into the bathroom 4 by an oversight in the course of sterilization and purification, the human body is detected by infrared rays, etc., a signal is sent to a controller 10, an operation of the ozone generating device 2 is stopped, and also, by operating an exhaust fan 11, ozone is allowed to pass through an exhaust pipe 12, and exhausted to the open air.