A distal end rigid member 11s, a prism 20 provided inside the distal end rigid member 11s and positioned at the rear in an optical axis direction of a lens for observing a site to be examined, an image pickup device 21 fixed to a light exit surface of the prism 20 inside the distal end rigid member 11 s, and a substrate 22 including a surface 22i fixed to the image pickup device 21 and another surface 22t fixed to an inner circumferential face 11sn of the distal end rigid member 11s are included, and the other surface 22t of the substrate 22 is formed in a shape that reduces or eliminates a space between the inner circumferential face 11sn of the distal end rigid member 11s and the other surface 22t of the substrate 22.
