To provide a simplified, compact and reliable magnet assembly body for a radial and a thrust bearing of a rotor 14.

A first and a second assembly bodies including at least one permanent magnet 42, 44, 48, 50 are arranged with intervals in an axial direction and the magnets are polarized to float the rotor 14. A magnetic flux between a stator and the rotor magnets is adjusted by coils 54a, 54b and electric energy to the coils is adjusted with an electric circuit to stabilize the rotor 14 in an axial direction and offset the same to inside or outside in an axial direction of the stator magnet corresponding to the rotor magnet.