To keep lubricating performance favorable by heating oil when cooling medium is easy to be dissolved in oil in an oil storage part provided in a casing of a compressor, for releasing cooling medium from oil and effectively utilize engine waste heat for heating oil in this case.

In a compressor 1 driven by a water-cooled engine, and provided with an oil pan inside or outside, a heat exchanger 150 to heat oil in the oil pan, and a linear three-way valve 36 and a bypass passage 37 to supply engine waste heat recovered at an engine cooling water circuit 30 to the heat exchanger 150 are provided, and when temperature is low in starting the compressor 1, the linear three-way valve 36 is controlled to supply engine waste heat to the heat exchanger 150 to heat oil in the oil pan.