Moisture in a refrigeration circuit is absorbed by means of a polyvinyl ether oil that has hygroscopicity and serves as a refrigerating machine oil. Therefore, even if a compressor comes to have an elevated temperature attributed to the employment of a refrigerant made of a single substance of R32, the insulating film of the built-in motor of the compressor is hard to hydrolyze. Moreover, by setting a saturated moisture amount of polyvinyl ether at a temperature of 30° C. and a relative humidity of 80% to 5000 ppm or more, a tensile strength retention rate of the motor insulating film made of PET or PEN, which can easily be processed, can be set to 50% or more, by which the deterioration of the insulating film can be prevented. Therefore, the performance of the refrigerating apparatus can be stabilized for a long term by avoiding the breakdown of the compressor.