PURPOSE: To provide a compressor with a gear box for an automobile air conditioning device which cools lubricating oil without using an exclusive oil cooling device, and prevents the lowering of the coefficient of traction of the lubricating oil.

CONSTITUTION: A gear box 20 in a compressor with a gear box for an automobile air conditioning device is provided with an oil reservoir 22 to store operating oil to lubricate the gear box, and the oil reservoir 22 is connected to the route of a hydraulic circuit 111 to connect other hydraulic working auxiliary machinery such as a hydraulic motor or the like and a hydraulic pump 112 for using it as a reservoir tank, and the hydraulic circuit 111 is provided with an oil cooler 116, and the operating oil is made to circulate through the hydraulic circuit 111 and cooled. Since the oil reservoir of the gear box is used as the reservoir tank on the hydraulic circuit, the structure of the hydraulic circuit can be simplified, and in addition, since the operating oil in the oil reservoir is cooled by the oil cooler on the hydraulic circuit, the coefficient of traction of lubricating oil can be kept at high value, and the compressor can dispense with a special operating oil cooling device, and reduce the number of components for improving loading ability onto the automobile.