To provide a supercritical refrigerating cycle device and its control method preventing the degradation of cooling capacity of other evaporators when low pressure drops at the start or the like of a compressor.

The supercritical refrigerating cycle device comprises the compressor 1 taking in a refrigerant and force-feeding it; a radiator 2 radiating the heat of a high pressure refrigerant discharged from the compressor 1; a high pressure control valve 12 reducing the pressure of the refrigerant which flows in from the radiator 2 side; a mechanical superheat control valve 14 reducing the pressure of the refrigerant which flows in from the radiator 2 side; a first evaporator 6 evaporating the refrigerant which flows out of the high pressure control valve 12; and a second evaporator 9 evaporating the refrigerant which flows out of the superheat control valve 14. The set value of the superheat control valve 14 regulates the flow of the superheat control valve 14 so that the high pressure exceeds the target pressure after the start of the compressor 1.