To provide a flat shield cable capable of increasing the strength against disconnection when the cable is bent in the width direction even if the conductor size of each signal line is reduced. A flat shield cable is characterized in that a drain line is provided on one side of a plurality of, parallel signal lines each having an insulating cover, a dummy line is provided on the other side of the signal lines, and the drain line, the signal lines, and the dummy line are covered with a shield tape, which is covered with an insulating sheath. Further, the shield tape includes a metal foil overlaying the lines, a polymer layer overlaying the metal foil, and an adhesive to securely attach the polymer layer to the insulating sheath. A method is provided to wrap the shield tape around the wires, press the shield tape and wires together, and cover them by the insulating sheath.