A rotating electric machine has a first frame and a second frame disposed at one axial end of a casing. The first and second frames have a first flange and a second flange, respectively, that protrude outwardly from the casing. The first and second flanges are fastened together by a through bolt. The first flange includes a recessed portion having a first curved portion, a second curved portion, and a third curved portion. A curvature radius of the third curved portion is greater than a curvature radius of the first curved portion and a curvature radius of the second curved portion such that a concentration of stress within the third curved portion that is caused by a fastening force of the through bolt may be reduced.