A structure for cooling a rotating electric machine has high ability to cool permanent magnets provided in a rotor of the rotating electric machine and enables the rotating electric machine to exhibit high ability. The rotating electric machine (M) has a stator (S), the rotor (R), and the permanent magnets received in magnet receiving holes arranged in a rotor core (RC) so as to extend from end to end between core end surfaces in the axial direction of the rotor core (RC). Magnetic flux leakage prevention spaces (H1, H2) in contact with the permanent magnets are arranged from end to end between the core end surfaces in the axial direction.A rotor cooling liquid supply path (rs) for supplying cooling liquid is provided in one of the core end surfaces. The cooling liquid is caused to flow into the magnetic flux leakage prevention spaces (H1, H2), and the permanent magnets are cooled by the cooling liquid flowing in the spaces (H1, H2).