A rotor of a rotating electrical machine is provided in which neither deterioration nor fluctuation in the cogging torque is caused and that causes neither physical enlargement nor cost increase. The rotor of a rotating electrical machine, provided with a plurality of magnetic poles 3 that are fixed on a rotor iron core 2 and arranged spaced apart from one another in the circumferential direction of the rotor iron core 2, is characterized by including a tube-shaped non-magnetic ring 4 mounted on the outer circumferential surfaces of the plurality of magnetic poles 3, and characterized in that the non-magnetic ring has a plurality of inner-diameter bulging portions 41 that abut on the corresponding outer circumferential surfaces of the plurality of magnetic poles.