a hard endoscope is disclosed having a hard outer tube , an inner tube disposed eccentrically within the outer tube , such that a gap is left between the two tubes , the inner tube having an observing optical system disposed therein , a plurality of light guide fibers disposed within the gap , the light guide fibers being adapted to transmit light along the length thereof and an end surface formed by the termination of the outer tube , the inner tube , and the light guide fibers . the outer tube has a tip member disposed on the end thereof , the tip member having an opening and forming a curved inner peripheral surface . the inner tube has a tip member disposed on the end thereof , the tip member having a curved outer peripheral surface and a slit for receiving reflected light , and the inner tube tip member terminating at the above - mentioned opening . the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube are curved in generally the same direction . the light guide fibers disposed between the two peripheral surfaces are also curved , curves thereof having various different curvatures , such that the light which is emitted therefrom is emitted in different directions .