Abstract: According to the invention, the fiber scope is inserted into the highly rigid tube and this tube is clamped as a rigid member by the robot wrist (or fiber scope supporting device) and camera supporting device, thereby allowing the camera supporting device and tube to move intergrally with the robot wrist. Therefore, no twisting of the fiber scope occurs within the operating range of the robot wrist axis. Also, even at any position in the operating range of the robot wrist axis as well, the angle of bend of the fiber scope can be held to a constant value below the allowable bending angly of the fiber scope. Consequently, it has been possible to realize an imaging device in which interference between the object to be worked and the optical system is remarkably improved.