PROBLEM TO BE SOLVED: To smoothly continue defrosting operation and shorten time for the defrosting operation. SOLUTION: This air conditioner includes a refrigerant circuit (10) having two outdoor heat exchangers (17) interconnected in parallel. During the defrosting operation, in the refrigerant circuit (10), a refrigerant is circulated in the direction reverse to that during heating operation so as to defrost the two outdoor heat exchangers (17) simultaneously. During the defrosting operation, when defrosting of either one of the outdoor heat exchangers (17) is completed, an opening of an outdoor expansion valve (18) corresponding to the outdoor heat exchanger (17) is reduced. Then, when a suction superheat degree of a compressor (11) exceeds a predetermined value, shortage of refrigerant circulation amount in the refrigerant circuit (10) is determined, and the opening of the outdoor expansion valve (18) with the reduced opening is increased. After that, when the suction superheat degree of the compressor (11) is lowered to less than the predetermined value, it is determined that the refrigerant circulation amount is recovered, and the opening of the outdoor expansion valve (18) with the increased opening is reduced again. COPYRIGHT: (C)2010,JPO&INPIT