Abstract: An electric rotary machine such as a motor has a rotor having a plurality of poles, a stator having a plurality of poles confronting the poles of the rotor in a radial direction, and a casing, for the rotor, having a cylindrical portion which extends in an axial direction. A permanent magnet composed of a mixed material of magnetic powder and a binder being a thermosetting resin constitutes the poles of the rotor. The permanent magnet, which is ring-shaped, is mounted in the casing along an inner circumference of the cylindrical portion of the casing in a circumferential direction. A yoke member is mounted around an outer circumference of the cylindrical portion of the casing, and a plurality of openings penetrate the cylindrical portion and the yoke member at the same time. The permanent magnet has a plurality of projections monolithically formed on its outer circumference. The projections are fitted in the respective openings in the yoke member and cylindrical portion.