PURPOSE: To suppress the rise of blowout temperature at the time of refriqerant not flowing to an air conditioning evaporator to the minimum without decreasing blowout air quantity at the time of letting refrigerant flow alternately to the air conditioning evaporator and an evaporator for a refrigerator to obtain both cooling and refrigerating functions, thereby reducing discomfort felt by passengers.

CONSTITUTION: When a solenoid valve for supplying refrigerant to an air conditioning evaporator is closed to cut off refrigerant flow to the air conditioning evaporator and that an intake door is placed in the outside air lead-in position to have high outside air temperature (when the judgment of steps 103, 104, 105 is all affirmative), the intake door is switched into the inside air lead-in position from the outside air lead-in position (106), and an air mixing door is corrected to the cooling side (108). The lead-in of hot outside air is thereby impeded, and the air quantity passing a heater is reduced to suppress the rise of blowout temperature.