PURPOSE: To make it possible to prevent the temperature of a large capacity transistor of an inverter circuit from rising during space heating by providing a control part for operating an outdoor fan at the time of space heating in accordance with the temperature from a temperature detector.

CONSTITUTION: A CPU 28 carries out controls necessary for space cooling/heating operation such as temperature setting from a room temperature setting part 31, varying the frequency of an inverter circuit 20 based on detected temperatures of respective sensors 29 and 30, and changing over of a two-way solenoid valves 9 and 10 at the time of space cooling. In addition thereto, the CPU 28 receives the detected temperature of a temperature sensor 27. At the time of space heating, when the detected temperature reaches a temperature zone where cooling determined by the heat resisting temperature of a giant transistor 21, CPU 28 actuates an outdoor fan 12. Further, when the detected temperature from a temperature sensor 27 is lower than a temperature T2 which has enough room for the heat resisting temperature of the giant transistor 21, the CPU 28 stops the operation of the outdoor fan 12. That is, at the space heating mode operation only when the detected temperature reaches a temperature higher than a predetermined temperature at which cooling is required, the outdoor fan 12 rotates, and the outdoor fan 12 is operated in accordance with the temperature of a heat sink 26.