PURPOSE: To improve the correlation between the detected temperature of a car- interior temperature sensor and a car-interior temperature by increasing the revolution speed of an aspirator fan for supplying air into the car-interior temperature sensor so that the difference between a set temperature and the car-interior temperature becomes below a certain value.

CONSTITUTION: When an air conditioner is started and the switch 39 of a blower is turned to AUTO, the output corresponding to the synthetic thermal load amount corresponding to the temperature signal Td of a temperature setting device 9 and the temperature signal Tr detected by a car-interior temperature sensor 8 is outputted from an operation amplifier 15 or 17, and when the output Vt exceeds a standard voltage V2, each output of operation amplifiers 20 and 21 becomes H, and a driving circuit for a motor 35 at high or medium speed which includes a resistor 36 is formed, and the blower revolves at high or medium speed. While, the output of the operation amplifier 20 becomes H, and a transistor 40 is put into electric conduction, and a driving circuit for a motor 13 at high speed which bypasses a speed adjusting resistor 41 is formed, and also an aspirator fan revolves at high speed. Therefore, the following performance of a car-interior temperature sensor to the room temperature can be improved.