A flat cable in which at least end portions of a plurality of coaxial cables are securely arranged in parallel on a sheet is characterized in that a flat cable edge-machined portion for electric connection of the coaxial cables is formed at the end portion of the plurality of coaxial cables, and a part of the sheet is made to remain in a band shape across an entire width of the flat cable between a machined edge portion of the edge-machined portion and a distal end of the flat cable, and a jacket of the coaxial cable is secured to the band-shaped sheet.