The invention provides an electric rotating machine comprising: an electric rotating machine section provided with a rotor including a rotary shaft and a stator including an armature winding that is disposed so as to surround the rotor; and a switching circuit section that is located in the proximity of the electric rotating machine section, and is provided with at least one pair of switching elements forming an upper arm and a lower arm to make a switching control of the electric rotating machine section; and in which the switching elements of each arm of the switching circuit section are connected at respective drain terminals to individual heat sinks with no insulator interposed, and the individual heat sinks are made integral with each other via an insulator.