An optical module for connecting a ferrule for connecting an optical fiber and a photoelectric transducer mounted on a substrate includes first lenses, second lenses, and a dummy lens. The first lenses are provided on a first side of the optical module to which the ferrule is to be connected. The second lenses and the dummy lens are provided on a second side of the optical module facing a surface of the substrate. The second lenses and the dummy lens are aligned on the same line. An image of the dummy lens is reflected from a mirror to be projected onto a plane on the first side of the optical module.