A connection member (21), which electrically connects a package (14) on which an optical element that converts an electric signal to an optical signal or converts an optical signal to an electric signal and at least one end portion including an incident/releasing port for an optical signal of an optical waveguide (11) that is optically coupled with the optical element to transmit the optical signal are mounted, and a second substrate (2) to each other, is provided with a holding unit having elasticity, which holds the package (14), and a connection unit that is connected to the substrate (2).