To reduce a cost by obviating an emergency bearing by housing a sliding member having a low friction coefficient in respective grooves in the shaft direction of a relative rotation surface of at least one of a magnetic bearing, a stator and a rotor so as to project from the peripheral surface.

For example, a laminated iron core 6a is formed in a stator 6S of an electric motor by laminating an iron plate in the shaft direction. A slot 6b is formed in the shaft direction on the inner peripheral surface of this laminated iron core 6a so that a coil 6c is housed in it. A wedge 6d is fitted in the opening part of the slot 6b through a liner 6e as a presser of the coil 6c. Here, the wedge 6d is formed of Teflon, and the surface of the wedge 6d projects from the inner peripheral surface of the laminated iron core 6a in a wedge 6d-fitted state. Therefore, an installing space and a part can be reduced by obviating a conventional emergency bearing, and the degree of a dangerous speed can be reduced by shortening the shaft length while reducing size and a cost.