A refrigeration device (1, 101) comprising: a compression mechanism configured to compress a refrigerant; a radiator connected to a refrigerant discharge side of said compression mechanism; a first expansion mechanism connected to an exit side of said radiator; a liquid receiver connected to a refrigerant outflow side of said first expansion mechanism; a second expansion mechanism (17, 33a, 33b) connected to an exit side of said liquid receiver; an evaporator (31, 31a, 31b) connected to a refrigerant outflow side of said second expansion mechanism and to a refrigerant intake side of said compression mechanism; and a control unit for minimizing the degree of pressure reduction by said first expansion mechanism when the refrigerant that flows from the refrigerant discharge side of said compression mechanism to a refrigerant inflow side of said first expansion mechanism has undergone a transition from a supercritical state to a subcritical state, characterized in that said refrigeration device further comprises a pressure detector provided between the refrigerant discharge side of said compression mechanism and the refrigerant inflow side of said first expansion mechanism, wherein said control unit is configured to minimize the degree of pressure reduction by said first expansion mechanism when the pressure detected by said pressure detector is equal to or less than a predetermined pressure; or in that the refrigeration device further comprises a first temperature detector provided to a first specific region of said radiator; and a second temperature detector provided to said first specific region of said radiator, wherein said control unit is configured to minimize the degree of pressure reduction by said first expansion mechanism when the difference between the temperature detected by said first temperature detector and the temperature detected by said second temperature detector is equal to or less than a predetermined threshold value. a compression mechanism configured to compress a refrigerant; a radiator connected to a refrigerant discharge side of said compression mechanism; a first expansion mechanism connected to an exit side of said radiator; a liquid receiver connected to a refrigerant outflow side of said first expansion mechanism; a second expansion mechanism (17, 33a, 33b) connected to an exit side of said liquid receiver; an evaporator (31, 31a, 31b) connected to a refrigerant outflow side of said second expansion mechanism and to a refrigerant intake side of said compression mechanism; and a control unit for minimizing the degree of pressure reduction by said first expansion mechanism when the refrigerant that flows from the refrigerant discharge side of said compression mechanism to a refrigerant inflow side of said first expansion mechanism has undergone a transition from a supercritical state to a subcritical state, characterized in that said refrigeration device further comprises a pressure detector provided between the refrigerant discharge side of said compression mechanism and the refrigerant inflow side of said first expansion mechanism, wherein said control unit is configured to minimize the degree of pressure reduction by said first expansion mechanism when the pressure detected by said pressure detector is equal to or less than a predetermined pressure; or in that the refrigeration device further comprises a first temperature detector provided to a first specific region of said radiator; and a second temperature detector provided to said first specific region of said radiator, wherein said control unit is configured to minimize the degree of pressure reduction by said first expansion mechanism when the difference between the temperature detected by said first temperature detector and the temperature detected by said second temperature detector is equal to or less than a predetermined threshold value.