With regard to an end portion shape of a slit formed in a rotor core in which flux barriers are formed in a circumferential direction in an identical number to the number of poles by arranging one or more slits and core layers alternately in a radial direction, an end portion of a slit is shaped such that, when mg is set as the number of slit end portions, ni is set as a natural number no smaller than 1, α and β are set as numbers within a range of −¼ to ¼, q is set as a natural number no smaller than 1, and Ns is set as the number of slots, intervals δgi and εgi from a first slit end to an ith slit end of a slit wall on an identical circumferential direction side satisfy specific mathematical formulae.