The semiconductor module includes a semiconductor chip and a semiconductor chip. The semiconductor chip includes an optical device such as an optical waveguide, an optical receiver, and a grating coupler, and a wiring formed over the optical device. The semiconductor chip includes a semiconductor element such as a MISFET formed in the semiconductor substrate, and a wiring formed over the semiconductor element. a top surface of the semiconductor chip is laminated to a top surface of the semiconductor chip such that the wirings are in direct contact with each other. In the semiconductor substrate, a through hole having a circular shape in plan view is formed, in the through hole, an insulating film is formed as a cladding layer, and the semiconductor substrate surrounded by the through hole constitutes an optical waveguide.