A rotating machine with a permanent magnet rotor that is easier, lower cost, and lighter includes a plurality of permanent magnet assemblies (20) mounted on a rotor body (1). The magnet assemblies (20) are mounted via magnet holders that each include a pair of claws (2, 3) connected by a bridge (5) and forming a seat for a respective magnet assembly (20). The claws have terminal expansions (11) that extend beyond the bridge (5) and form a second seat in which a tightening section (9) is received. The claws (2, 3) can elastically pivot about the bridge (5) when the terminal expansions (11) are squeezed together or forced apart, allowing insertion of and securing the magnet assembly, respectively.