There is provided a slip ring device in which three ring members through are provided so as to be lined up in sequence along an axial line of an input shaft and brushes contact with the ring members respectively, three inner bus bars are provided and are supported by a sleeve portion of the input shaft, and contacting groove portions are provided so as to dent in the radially outwards direction into the inner circumferential surfaces of the ring members and extend along the axial line direction, with one end portions of the inner bus bars being set into these contacting groove portions respectively.