A rotating electrical machine includes a flange provided at one end of a hollow frame in an axial direction; a rotor including a shaft, the shaft being rotatably supported by the flange; and a stator fixed to an inner section of the frame, the stator surrounding the rotor. The rotor includes a first rotor core and a second rotor core arranged in the axial direction and having recesses formed in the axial direction, and a rotor-core space defined by the recesses that are formed in the first rotor core and the second rotor core and that face each other.