the blowing unit 18 through the suction passage 32 formed at an inner area of the seat plate 12 the suction passage 32 is formed along the margin of the seat plate 12 the lid 14 is hinged to an upper side of the body 10 with the seat plate 12 which is a known art the water tank 16 is also a known art as illustrated in fig4 and 5 the blowing unit 18 is a blower which includes a case 33 a fan 34 mounted inside the case 33 for allowing the air to be tangentially introduced and to be axially discharged a motor 36 for driving the fan 34 and a battery 38 for supplying a power to the motor 36 the blowing unit 18 is mounted with an exhaust duct 40 at an air discharge side the exhaust duct 40 is formed thereunder with a discharge outlet 42 at a predetermined distanced place from the blowing unit 18 and is coupled therein to air blocking means 44 for opening and closing the discharge outlet 42 in response to operation of the blowing unit 18 the discharge outlet 42 is connected to an exhaust pipe 46 communicating with the drain passage 24 the case 33 of the blowing unit 18 is connected to a suction duct 48 communicating with the suction passage 32 the.