An optical module includes a first board that includes a recessed portion and a first conductor layer, a second board accommodated in the recessed portion and includes an optical waveguide and a second conductor layer, a semiconductor element installed across the first board and the second board and coupled to the first conductor layer and the second conductor layer, and a first bonding material disposed between a sidewall and a bottom surface of the recessed portion and the second board so as to bond the first board and the second board to each other.