A shielded flat ribbon cable includes a plurality of insulated conductors being spaced parallel to each other, the insulated conductors each including an inner conductor and an insulation coating the inner conductor; an outer conductor bundling the insulated conductors together, the outer conductor including a first shell and a second shell in association with each other to sandwich the insulated conductors therebetween, each of the first shell and the second shell including a plurality of grooves covering outer surfaces of the insulated conductors, and a plurality of edge portions integral with both sides of the grooves, and gap formation-suppressing means for suppressing formation of gaps between the edge portions of the first shell and the edge portions of the second shell, respectively.