An ejector refrigerant cycle device includes a radiator for radiating heat of high-temperature and high-pressure refrigerant discharged from a compressor, a branch portion for branching a flow of refrigerant on a downstream side of the radiator into a first stream and a second stream, an ejector that includes a nozzle portion for decompressing and expending refrigerant of the first stream from the branch portion, a decompression portion for decompressing and expanding refrigerant of the second stream from the branch portion, and an evaporator for evaporating refrigerant on a downstream side of the decompression portion. The evaporator has a refrigerant outlet coupled to the refrigerant suction port of the ejector. Furthermore, a refrigerant radiating portion is provided for radiating heat of refrigerant while the decompression portion decompresses and expands refrigerant. For example, the refrigerant radiating portion is provided in an inner heat exchanger.