The purpose of the invention is to provide an air conditioning device that can perform defrost operations more efficiently than conventionally. An air conditioning device (100) configured by a compressor (1), an outdoor heat exchanger (3), an indoor heat exchanger (5), and a four-way valve (2) that is provided closer to the discharge side of the compressor (1) than the outdoor heat exchanger (3) and closer to the discharge side of the compressor (1) than the indoor heat exchanger (5) being connected comprises: a fan (31) to blow air onto the outdoor heat exchanger (3); a power source device to supply power to the fan (31); a fan input detecting means for detecting a physical quantity pertaining to the power supplied to the fan (31); and a controlling means (80) for controlling the four-way valve (2) to switch between a first operation in which the outdoor heat exchanger (3) is caused to function as an evaporator and a second operation in which the outdoor heat exchanger (3) is caused to function as a condenser. If the physical quantity detected by the fan input detecting means is equal to or greater than a reference quantity, the first operation is switched to the second operation. The controlling means (80) adjusts the reference quantity so that the reference quantity when the temperature of refrigerant flowing through the outdoor heat exchanger (3) is high is less than the reference quantity when the temperature of the refrigerant flowing through the outdoor heat exchanger (3) is low.
