A refrigerant cycle device includes a branch portion for branching a flow of refrigerant discharged from a compressor, a first radiator for radiating one high-temperature and high-pressure refrigerant branched at the branch portion, an ejector including a nozzle portion for decompressing refrigerant on a downstream side of the first radiator, a second radiator for radiating the other high-temperature and high-pressure refrigerant branched at the branch portion, a throttle device for decompressing refrigerant on a downstream side of the second radiator, and a suction side evaporator for evaporating refrigerant downstream of the throttle device and for allowing the refrigerant to flow to an upstream side of a refrigerant suction port of the ejector. Furthermore, the first and second radiators are disposed downstream of the branch portion such that a heat radiation amount of refrigerant in the first radiator is smaller than that in the second radiator.