Abstract: A connecting means for an illuminant handpiece being characterized in that the connecting device is adapted such that at least one of the electrical connections of the electric power receiving terminals of the illumination lamp and the electric power supply terminals is performed by fitting at a position close to the axis of the grip section almost symmetrically about the axis, and the other electrical connection is performed by fitting almost symmetrically about the axis or by abutting coaxially about the axis so as to permit a mutual rotation of the terminals. With this structure, the diameter of the connection area can be made small and the grip section can have an easy-to-hold size. In addition, the distance to the irradiation section can be reduced and efficient irradiation with less optical loss is obtained. Moreover, the space or lamp replacement can be reduced.