PURPOSE: To provide a highly reliable flat cable with wire holder by subjecting the end part of a flat cable to conductor peeling and zigzag forming works, sticking long and short tapes to it, respectively, and inserting it into the through hole of a wire holder having a locking part.

CONSTITUTION: A plurality of resin insulated wires are juxtaposed, a thermally fusing tape 4 is adhered to it at places to form a flat cable 3. The flat cable 3 is cut, the end part is subjected to conductor peeling work and then zigzag forming work to form a conductor peeled part 5. Two kinds of tapes 6, 7 different in length from the cover resin ends of a resin covered wire are stuck to both surfaces of the end part. This end part of the flat cable 3 is inserted to the through hole 10 of a wire holder 1, and the short-side tape 6 is engagingly locked by a locking part 8 in the through hole. After the wire holder 1 in the temporarily inserted state is mounted on a base 2, the flat cable 3 is pushed to engage the long-side tape 7.