To improve heat-exchanging performance and comfortableness of an air conditioner by controlling the degree of superheating of a refrigerant to a set target value at cooling time and the degree of supercooling of the refrigerant to a set target value at heating time by means of pressure-reducing mechanisms, respectively installed to a plurality of independent refrigerant circulating routes.

An air conditioner is provided with a target degree-of-superheat value storing section 9, which stores the target degree-of-superheat value of a refrigerant, corresponding to the temperature differences between the temperature detected by means of a suction temperature sensor 6 and the temperature detected by means of first and second indoor heat- exchanging temperature sensors 7a and 7b, a degree-of-superheat detecting section 10 which detects the actual degree of superheat of the refrigerant, and target degree-of-supercooling value storing section 11, which stores the target degree-of-supercooling value of the refrigerant corresponding to the temperature difference between the temperatures detected by means of first and third indoor heat-exchanging temperature sensors 7a and 7c, and the temperatures detected by means of second and fourth indoor heat-exchanging temperature sensors 7b and 7d. The air conditioner is also provided with a degree-of-supercooling detecting section 12, which detects the actual degree-of-supercooling of the refrigerant and a valve travel correcting section 13 which corrects and controls the travels of first and second expansion valves 4a and 4b, so that the detected results of the detecting sections 10 and 12 become target values.