An optical coupling structure that interfaces between optical devices mounted on a substrate and optical waveguides formed in the substrate. A manufacturing method includes preparing a wafer formed on an inorganic solid material on a dicing tape and cutting the back surface of the wafer to form substantially angled portions using a dicing blade having a point angle. The dicing tape is stripped from the wafer and the wafer is separated at the valleys between the substantially angled portions to obtain an optical coupling element. The obtained optical coupling element is a three-dimensional polyhedral light-reflecting member having a mirror surface corresponding to a surface of the wafer. The obtained optical coupling element is inserted into a trench that opens, substantially perpendicular to an optical waveguide of an optical transmission substrate, in the main surface of the optical transmission substrate to provide a structure for optical coupling with the outside.