To effectively lower the temperature of a part of a vehicle where the interior temperature is high by operating an operating means by a control means in the direction where the temperature detection value by a sensor means 9 for detecting the interior temperature condition is the maximum, directing an injection port of a water sprayer to spray fog.

In summer, during parking or engine stop under the blazing sun, a controller 21 judges according to detection values of plural sensor means 9 installed in plural spots of a vehicle, and controls a motor in such a manner that a spray port 25 of a rotating part of a water sprayer 5 is turned to the direction having the maximum value of the above detection values to spray fog. Thus, fog is sprayed partially, so that in the case of partially spraying, the operating time of the water sprayer 5 may be shorter as compared with the case of uniformly spraying over the whole surface of the interior, and further the interior temperature of the vehicle can be lowered effectively.