An illumination optical system unit 26A includes an optical fiber 39A, a fluorescent body 40, a ferrule 60 as a holding member that holds the fluorescent, body 40 and the optical fiber 39A, a cylindrical first sleeve member 61 that covers the outer periphery of the fluorescent body 40, and a protective cover 38 that seals the tip side of the fluorescent body 40. The ferrule 60 holds the optical fiber 39A and the fluorescent body 40, and is inserted into the first sleeve member 61. A magnetic metal film 67 is provided on the surface of a fluorescent body-holding portion 69 of the ferrule 60. The tip of the protective cover 38 and a magnet 75 are allowed to come into contact wife each other to generate magnetic force between those two, so that the fluorescent body 40 comes into close contact with the protective cover 38.