To provide the rotor unit of a motor having an inexpensive and simple structure.

The rotor unit of a motor comprises a resin bush 3, a rotating shaft 1 press fitted in the shaft hole of the resin bush and integrated, a plurality of ring-like permanent magnets 2a and 2b arranged on the outer circumferential surface of the resin bush, and a ring-like member 5 arranged between the plurality of permanent magnets and positioning the permanent magnet on the outer circumferential surface of the resin bush.