A shielded flat cable comprises a plurality of rectangular conductors aligned parallel to one another; a pair of resin insulation layers that sandwich the plurality of rectangular conductors from bothsides of a plane in which the plurality of rectangular conductors are aligned parallel to one another such that the rectangular conductors are covered apart from the ends thereof in the longitudinaldirection; a shield layer in contact with the outer surface of at least one resin insulation layer among the pair of resin insulation layers; and a pair of first resin films, each being equipped withan adhesive, covering the outer surface of the pair of resin insulation layers or of the shield layer. Among the pair of resin insulation layers, the resin insulation layer in contact with the shieldlayer has a dielectric loss tangent of 0.001 or lower at 10 GHz. The adhesive or the pair of first resin films comprises a flame-resistant material.