The object of the invention is a rotor for an electrical machine excited by permanent magnets, said rotor comprising a substantially cylindrical magnetic body of the rotor fitted onto the shaft of the electrical machine and a set of permanent magnets used to create a first and a second pole alternately in the circumferential direction, excited in opposite directions. The permanent magnets are fitted into openings arranged within the rotor. The rotor comprises a body part with several segments extending to the outer circumference in the circumferential direction and an outward tapered section remaining between the segments in the radial direction of the rotor. Permanent-magnet pieces are arranged between each section and segment.