PURPOSE: To enhance reliability of rotor by making stop grooves oppositely in the outer periphery of rotor core and the inner periphery of permanent magnet, fitting flexible stop members in the grooves and filling the grooves with a filler, thereby securing the permanent magnet rigidly.

CONSTITUTION: Stop grooves 4 are made oppositely in the outer periphery of a rotor core l and the inner periphery of a permanent magnet 3 and stop members 5 are fit in the stop grooves 4. Adhesive is provided on the bonding faces of the rotor core 1 and the permanent magnet 3 and in the stop grooves 4. The stop grooves 4 are skewed because the core is skewed but since the stop member 5 is made of flexible resin or metal, it can be fit in the skewed stop groove 4 while being bent. Furthermore, the flexible stop member 5 minimizes the gap with respect to the stop groove 4 thus eliminating play at the stop part.