An optical fiber board has a substrate, optical fiber arranged as wiring on the substrate, and extension portions in each of which some optical fibers are led out from the substrate to be adjacent to each other in a row. The adjacent optical fibers at a base portion of the extension portion are not fixed to one another. The adjacent optical fibers at a forward end portion of the extension portion are fixed to one another integrally. The base portion has a predetermined length from an edge portion of the substrate.