To provide a device with a fine bubble generating function such as a bath device for allowing a comfortable cloudy bath by fine bubbles for instance.

An exit side conduit is connected to a water lead-out port side of a pressurized container 30 to which water or air-containing water is pressurized and introduced and is connected to a bathtub 26, and an air introducing valve 38 and a pump (circulation pump) 21 are interposed in the water entrance side conduit of the pressurized container 30. The pump 21 sends the water to the side of the pressurized container 30 in the closed state of the air introducing valve 38, and sends the water and the air introduced from the outside to the entrance side conduit through the air introducing valve 38 to the side of the pressurized container 30 in the open state of the air introducing valve 38. Switching control is executed between the function of an air layer non-forming mode of driving the pump 21 by a rotation number equal to or larger than a set rotation number and intensely agitating the water inside a tank such that an air layer is not formed inside the tank of the pressurized container 30, and the function of an undissolved air layer forming mode of driving the pump 21 by the rotation number smaller than the set rotation number and forming the air layer inside the tank of the pressurized container 30.