Abstract: A stator of an A.C. electric motor includes a magnetic core comprising a magnetic ring member and two "U"-shaped magnetic members connected to the ring member. The two "U"-shaped magnetic members hold the ring member therebetween and are angularly spaced from one another around the central axis of the ring member. A primary winding is wound on one of the two "U"-shaped member and a secondary winding is wound on the other "U"-shaped member. The secondary winding is short-circuited by a capacitor. When A.C. voltage is applied to the primary winding, A.C. voltage is induced on the secondary winding at a certain value or more of the primary voltage. A rotary flux is formed in the ring member by magnetic fluxes induced by primary and secondary A.C. currents. Accordingly, a cage rotor or magnet rotor which is rotatably disposed in the ring member can be rotated.