A rotating electrical machine includes a frame, a flange, a rotor, a stator, and a plurality of reinforcing bars. The frame has a plurality of side surfaces surrounding a space to form a substantially polygonal shape in a plane perpendicular to an axial direction of the frame. The side surfaces have a first side surface and a second side surface opposite to the first side surface. The frame has an end portion in the axial direction. The flange is provided at the end portion of the frame. The rotor is provided in the space and includes a shaft that is rotatably supported by the flange. The stator is provided in the space to be fixed to an inner section of the frame and to surround the rotor. The reinforcing bars intersect each other and are provided on the first side surface and the second side surface, respectively.