The an optical communication module associated with the present invention comprises a semiconductor substrate, a light emitting element mounted on said semiconductor substrate to output light for transmission (transmitted light), a light receiving element mounted with an adhesive resin on said semiconductor substrate to convert light received (received light) to an electric signal and a wavelength filter to branch out the received light guided to said light receiving element and the transmitted light output from said light emitting element. A groove for an optical path, through which the received light passes to be guided to said light receiving element and a first protective groove formed around said groove for an optical path to block said adhesive resin from intruding into said groove for an optical path are formed on said semiconductor substrate.