An optical module includes: an optical device mounting board including a first surface, a second surface on the reverse side, and a light transparent part allowing an emitted light traveling from the first surface to the second surface and a received light traveling in the opposite direction to pass through the transparent part; an optical device mounted on the first surface, which is a light emitting device or a light receiving device; a first terminal mounted on a surface except the first surface of the optical device mounting board; a wiring connecting a second terminal of a component mounted on the first surface including the optical device with the first terminal; and a transmission medium connector connecting a light transmission medium transmitting the emitted light traveling from the second surface to an outside of the optical module or the received light traveling in the opposite direction.