The present invention provides a rotating electric machine and a method of detecting electric discharge (a defect detection method for a rotating electric machine), which are able to early detect vibration sparking between a stator winding and a stator core. A rotating electric machine of the present invention comprises a cylindrical stator including a stator core and a stator winding, a rotor disposed inside the stator, at least one key bar disposed on an outer periphery of the stator core and extended in an axial direction of the stator, and at least one current detector disposed on the key bar and configured to measure a current flowing in the key bar.