Stators 12 and 13 are disposed with required air gaps in an axial direction of a rotor 11 so as to face each other, a plurality of field bodies 15 or permanent magnets 33 are disposed in the rotor 11, and a plurality of armature coils 17 and 19 are disposed in the stators 12 and 13 around the axis. At least one of the field bodies 15 or permanent magnets 33 and the armature coils 17 and 19 are formed from a superconductive material such that their magnetic flux directions are directed to the axial direction.