A shielded flat cable includes a plurality of juxtaposed insulating layer-coated signal wires, a drain wire disposed on one side of the group of the signal wires, a shielding layer covering an outer periphery of the group of signal wires and drain wire, and an insulating sheath covering an outer periphery of the shielding layer. A conductor of at least the outermost signal wire of the plurality of signal wires which is remote from the drain wire is made of a copper alloy.