REFRIGERATION DEVICE

A refrigerating apparatus for keeping an inside of a storage at a predetermined low-temperature state includes first and second refrigerant circuits including compressors, condensers, decompressors, and evaporators, connected circularly with pipings to form refrigerating cycles, the circuit having a first or second refrigerant sealed therein as a working refrigerant, a first sensor which detects a temperature of a cascade condenser constituted by integrating the evaporator of the first refrigerant circuit and the condenser of the second refrigerant circuit in a heat exchangeable manner, a first controller which controls an operation performance of the first compressor in a variable manner based on a first-sensor-detected temperature in order that the first-sensor-detected temperature is a first temperature, a second sensor which detects a temperature inside the storage, and a second controller which controls an operation performance of the second compressor in a variable manner based on a second-sensor-detected temperature in order that the second-sensor-detected temperature is a second temperature.