To provide a bearing device capable of improving the accuracy and the service life and remarkably reducing the load torque when starting in comparison with a case of using any one of a dynamic pressure thrust bearing and an active magnetic bearing by combining the dynamic pressure thrust bearing with the active magnetic bearing so that the active magnetic bearing shows the static rigidity and the dynamic pressure thrust bearing shows the dynamic rigidity.

In this bearing device, a thrust bearing 25 having a non-rotating body for supporting a rotor 20 freely to be rotated and the lubricating fluid interposed between the rotor 20 and the non-rotating body and formed between the rotor and the non-rotating body supports the rotor in the thrust direction. Driving coils 46 and 48 are arranged in one of the rotor and the non-rotating body and magnets 56 and 58 are arranged in the other thereof so as to form an active magnetic bearing 40. A gap sensor 50 for detecting the axial directional space between the rotor and the non-rotating body is provided, and electrifying to the driving coils 46 and 48 is controlled by the output of the gap sensor so as to control the axial directional space between the rotor and the non- rotating body.