Permanent magnets 52a1, 52a2 are inserted into magnet insert holes 51a1, 51a4 formed in a main magnetic pole 50A of a rotor 50. An outer circumferential surface of the rotor includes a first outer circumferential surface portion 50a which intersects with a d-axis and second outer circumferential surface portions 50da, 50ab which intersect with a q-axis. A radius R2 of curvature of the second outer circumferential surface portions 50da, 50ab is larger than a radius of curvature of the first outer circumferential surface portions 50a. Recesses 50a1, 50a2 are formed in the second outer circumferential surface portions 50da, 50ab and in a position to face end walls 51a2, 51a5 of the magnet insert holes 51a1, 51a4 which are adjacent to the outer circumferential surface of the rotor. It is constructed such that [(74/P)°≦θ≦(86/P)°] and [(16/P)°≦α≦(48/P)°], where θ is a mechanical angle of the first outer circumferential surface portion 50a, P is the number of pairs of poles of the rotor 50, and α is a mechanical angle of the recesses 50a1, 50a2.