Magnet holding member used in rotating electrical machine, rotor, rotating electrical machine, and machine tool

A holding member used in a rotating electrical machine having a rotor and a plurality of magnets positioned on an outer peripheral surface of the rotor, the holding member being positioned radially outside of the magnets and configured to radially inwardly press and hold the magnets, wherein

• the holding member comprises a cylindrical shape formed by spirally winding a fiber bundle on the outer periphery of the magnet, which is unbroken over at least one traverse, from one axial end to the other axial end of the rotor outside the outer periphery of the rotor, the one traverse at least including a section where the magnets are positioned, among sections between the one axial end the other axial end of the rotor, and wherein
• the holding member is formed by a fiber reinforced resin including a resin as a matrix, and a termination treatment of at least a winding start end and a winding terminal end of the fiber bundle is carried out by using a first resin which is a reactive curable resin.