Magneto rotor

A rotor core, rotating in the vicinity of a generating coil, comprises a balance weight section and a pair of magnetic poles (3,4), provided on opposite sides of the balance weight section 2 with respect to a center of rotation O of the rotor core 1 to sandwich a magnet, and confronting through a magnetic gap G. A magnet holding section 9 for preventing the magnet 5 flying out through the magnetic gap G due to centrifugal force, is provided integrally contiguous to each of the magnetic poles so as to connect between the two magnetic poles.