The purpose of the present invention is to obtain an air conditioning device (100) with which it is possible to ensure that the refrigerant flow rate and the oil return rate to the compressor (1) are always appropriate to the operating conditions, making it possible to prevent decline in performance or diminished reliability despite changing operating conditions, such as the state of action of the refrigerant circuit or outdoor conditions. The device comprises: a first detector for detecting the refrigerant temperature inside an accumulator (11); a storage unit (30d) for storing information about two-layer separation temperature of a refrigerant and a refrigerant oil; a decider for comparing the refrigerant temperature and the two-layer separation temperature, and deciding that the refrigerant and a refrigerant oil are in a state of two-layer separation; a second detector for detecting the state of intake refrigerant to the compressor (1); and a control unit for adjusting the degree of opening of a flow rate adjustment valve (13), on the basis of the state of two-layer separation and the state of the intake refrigerant.