A connection structure of a plate shaped routing material and an electric connection box, includes a plate shaped routing material, an electric connection box, and a connection mechanism. The plate shaped routing material includes a belt like flat shaped conductor in which an outer surface is covered with an insulating coating, a connecting cut-out part in which a part of an edge part in one long side part is removed in a rectangular shape, a conductor piece part exposed from the insulating coating in the connecting cut-out part, and a cut-out edge part.