A flat cable includes a plurality of coaxial cables mutually arranged in parallel, the coaxial cable in which a cross-sectional area of a central conductor is 0.006 mm2 or less, and an insulating film having a base material, and a thermoplastic adhesive layer formed on the base material. The insulating film is stuck on only one side of a parallel plane of the plurality of coaxial cables, and the plural coaxial cables are fixed to the thermoplastic adhesive layer.
