This invention is concerning a rotary electric machine 1, this electric motor 1 being provided with an inner cylinder 2, a rotor 3 provided so as to be rotatable inside the inner cylinder 2, a stator 4 fixed to the inner cylinder 2 and separated via a gap from an outer periphery of the rotor 3, and an outer cylinder 8 that covers an entire periphery of the inner cylinder 2 and forms a space 15, which serves as a coolant passage, in conjunction with the inner cylinder 2, wherein both ends of the inner cylinder 2 and the outer cylinder 8 in an axial direction are fixed to each other by cylinder welding portions 9 formed by welding. Accordingly, a rotary electric machine that is small and light can be obtained at low cost.