Abstract: A fiber scope of the side-viewing type includes an image guide and two light guides disposed on both sides thereof in an objective part. The fiber scope is suitable for the observation of the surface of long articles assembled with narrow gaps therebetween as in an assembly of nuclear fuel rods in a nuclear reactor and a wide field of view can be secured even if an object to be observed stands within a point-blank range of an objective part. Also a plurality of long articles can be simultaneously observed by the fiber scope or the observation can be carried out while moving the fiber scope in the scanning direction. If the fiber scope is used in a radioactive environment, highly radiation resistant optical fibers are used.