An optical waveguide board is provided which includes a substrate, an optical path changing unit being formed on the substrate used to change a direction of an optical path of incident light from a direction being vertical to a surface of the substrate to a direction being horizontal to the surface of the substrate and to condense a luminous flux and an optical waveguide being formed on the substrate to carry out multi-mode transmission of a luminous flux fed from the optical path changing unit wherein, based on a spread angle of the luminous flux formed by the optical path changing unit, mainly light components to be transmitted in a zero-order mode to a three-order mode only, out of various kinds of modes for the multi-mode transmission, is transmitted through the optical waveguide.