A determination device includes a refrigerant circuit, an operation determination unit, and a refrigerant determination unit. The refrigerant circuit is made of a compressor, a condenser, an expansion mechanism, and an evaporator that are circularly connected. In a refrigeration cycle operation in accordance with a quantity of heat required by the condensers or the evaporators, the operation determination unit determines whether the refrigeration cycle operation can be normally carried out or not. Upon determination that the refrigeration cycle operation cannot be normally carried out, the refrigerant determination unit determines whether a refrigerant in the refrigerant circuit is regenerable or not, based on a result of the determination. Thus the determination device is provided by which an effort involved with determination as to whether the refrigerant is regenerable or not can be reduced.