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