An optical module has a structure for reducing the stress applied to a package. The optical module is structured so that an end face of a waveguide (37) of a planar lightwave circuit (30) is joined to a plurality of packages (40) storing therein optical elements so that the waveguide is optically coupled to the optical elements. The optical module includes a housing (3) storing therein a planar lightwave circuit and a plurality of packages in which an upper face of a protrusion (270) formed in the bottom section is fixed to the planar lightwave circuit (30). Each of the plurality of packages (40) is electrically connected to an electric part (22) provided in the housing (3) via flexible printed circuits (271a, 271b).