A rotating electrical machine includes: a case; a rotor; a stator; a control portion including a field circuit portion used to supply a current to a control circuit and the field winding; a power circuit portion controlling a stator current; a heat sink installed so as to cool the control portion and the power circuit portion; a first waterproof portion providing waterproofing to signal terminals of the power circuit portion and the field circuit portion; a second waterproof portion provided with through-holes from which a part of the control portion and the power circuit portion is exposed and providing waterproofing between the control portion as well as the power circuit portion and the heat sink; and insulation portions installed in the through-holes of the second waterproof portion and isolating the control portion and the power circuit portion from the heat sink.