An object of the present invention is to provide an electrical rotating machine that prevents heat generated from a stator winding from being transmitted to an inverter circuit. A rotor having a field winding, and a stator having a stator winding arranged so as to surround the rotor are provided. One end of a rear bracket is connected to the stator, and arranged inside the rear bracket is a heat sink assembly including a heat sink having switching elements for controlling the field winding and the stator winding mounted thereto. The heat sink assembly is fixed to protruding portions protruding from an end surface of the rear bracket.