PURPOSE: To simplify the structure and reduce the cost of a refrigerating machine provided with a pair of compressors by adopting a low-pressure dome type all- closed compressor for one and a high-pressure dome type all-closed compressor for the other for disusing a pressure-equalizing pipe and an oil equalizing pipe.

CONSTITUTION: A low-pressure dome type all-closed compressor 1 for one and a high-pressure dome type all-closed compressor 2 for the other are respectively adopted for disusing a pressure-equalizing pipe and an oil-equalizing pipe. A suction pipe 7 and a discharge pipe 8 of the low-pressure dome tpe all-closed compressor 1 are respectively connected to an evaporator 5 and a condenser 3. Meanwhile, a suction pipe 9 and a discharge pipe 10 of the high-pressure dome type all-closed compressor 2 are respectively connected to a low-pressure casing 11 and the discharge pipe 8 of the low-pressure dome type all-closed compressor 1, and the low-pressure casing 11 is operated as an accumulator of the high- pressure dome type all-closed compressor 2 for obtaining a compact-sized and low-cost compressor part.