Disclosed is a double-side-conducting flexible-circuit flat cable with cluster section, which includes a flexible circuit substrate, a first electrical conduction path, a second electrical conduction path, a plurality of first and second conductive contact zones. The flexible circuit substrate has a first surface and a second surface and includes, in an extension direction, a first connection section, a cluster section, and at least one second connection section. The cluster section is composed of a plurality of clustered flat cable components formed by slitting in the extension direction. The first and second electrical conduction paths are respectively formed on the first and second surfaces of the flexible circuit substrate and each extends along one of the clustered flat cable components of the cluster section. The plurality of first and second conductive contact zones are respectively arranged on the first and second surfaces of the flexible circuit substrate at the first connection section. Each of the first and second conductive contact zones extends along one of the electrical conduction paths of the cluster section toward the second connection section.