JPH0552928B

PURPOSE:To change the quantity of illuminating light so that a good illumination can be executed in accordance with a size of a body to be inspected, by forming a fitting part containing an image pickup optical system, on the tip part of an inserting part, and providing an illuminating unit so as to be freely attachable and detachable. CONSTITUTION:A fitting part 3 which has a smaller diameter than that of an inserting part 1 and is formed a male screw 2 on the outside peripheral surface is set to the tip part of the inserting part 1, and on the bottom wall of a recessed part 4, a solid-state image pickup element 7 is provided so as to be opposed to an objective lens 5. Also, plural illuminating windows 8 consisting of cover glass are formed in the periphery of the objective lens 5, and the tip of a light guide 9 consisting of an optical fiber bundle is opposed to them. Moreover, to the fitting part 3, illuminating units 10, 20 to which a lamp 13 has been installed are fitted so as to be freely attachable and detachable. For instance, when a contact plate 15 is brought into contact with contact pins 17, 18 by screwing a body 11 of the illuminating unit 10 to the fitting part 3, and a switch is turned on, the lamp 13 is turned on. In this regard, when the inside diameter of the tube of a body to be inspected is small, and when said diameter is large, the inspection is executed by installing the illuminating unit 10 and the illuminating unit 20 to the fitting part 3, respectively.