An LED-type distal end optical adapter includes a three-dimensional molded substrate including a through hole and provided with a mounting surface and wall surface parts provided so as to project from the mounting surface, an adapter frame member including a small diameter hole in which an outer circumferential surface of the first wall surface part of the three-dimensional molded substrate is disposed and forming a first adhesive filling space, and a lens holding frame disposed in a through hole and forming a second adhesive filling space.
