Abstract: Disclosed is a dual air-conditioner for cars comprising an electromagnetic valve disposed in a refrigerant passage immediately downstream an outlet of an auxiliary evaporator for controlling the cross-sectional area of the passage, and an internal pressure balancing type expansion valve disposed in the refrigerant passage immediately upstream an inlet of the auxiliary evaporator. The passage cross-sectional area is controlled by the electromagnetic valve to control the pressure prevailing in the refrigerant passage between the expansion valve and electromagnetic valve so that the opening of the expansion valve is varied to regulate the flow rate of the refrigerant flowing into the auxiliary evaporator to thereby control the temperature of blow-off cooled air from the auxiliary evaporator.