A power transmission apparatus, which is disposed on a power transmission path from an output shaft of an internal combustion engine to a transmission in a vehicle, is provided with a rotating electrical machine including a rotor and a stator. The rotor is coupled to a synchronous rotating member that rotates synchronously with the output shaft of the internal combustion engine, and takes a central axis of the output shaft of the internal combustion engine as a rotating shaft. The stator is fixed to a fixing member on a non-rotating side with respect to the synchronous rotating member, and faces the rotor with a first gap therebetween.