<p>A cooling oil circuit (20), for circulating cooling oil cooled by an evaporator (14) on a refrigerant circuit (10) between it and a machine tool, is provided. A bypass circuit (24) is provided on the cooling oil circuit (20) to allow cooling oil to bypass a spindle (21) and limit a cooling capacity for the spindle (21), and a flow regulating valve (25) is provided on the bypass circuit (24). The opening regulating of this flow regulating valve (25) can regulate a cooling capacity limiting level, whereby the cooling capacity of a compressor (11) is controlled quicker than by a capacity control by inverter control.</p>
