To hold down the power consumption during the operation of an evaporative cooling device and reduce the cost of the evaporative cooling device by continuously operating a fan and a water sprayer when the detected temperature of a temperature sensor is above a designated value, and continuously operating the fan and intermittently operating the water sprayer when it is below the designated value.

An evaporative cooling device comprises a fan 4 for feeding atomized water emitted from a water sprayer 5 into the interior 11, power supply means 2, 3 for supplying power to the fan 4 and the water sprayer 5, and a sensor means 9 for detecting the interior temperature of a vehicle 1. After the fan 4 and the water sprayer 5 are operated for a fixed time, the temperature in the interior is detected by the sensor means 9. When the detected temperature in the interior 11 by the sensor means 9 becomes higher, the water sprayer 5 and the fan 4 are continuously operated to quickly lower the interior 11 temperature, and when it becomes below a designated temperature, the fan 4 with a small power consumption is continuously operated and the operation of the water sprayer 5 with a large power consumption is intermittently conducted.