To provide a super-extra-fine coaxial cable having very excellent bending resistance and having excellent electromagnetic shield characteristics, and to provide a manufacturing method thereof.

The super-extra-fine coaxial cable is provided with an inner conductor, an insulator resin layer arranged at an outer periphery of the inner conductor, and an outer conductor formed by laterally winding a metal foil wherein the whole surface is coated with dielectric resin on the outer periphery of the insulator resin layer, or further, the super-extra-fine coaxial cable is provided with a protective covering resin layer arranged at the outer periphery of the outer conductor, and the insulator resin layer and the outer conductor are firmly fixed in an integrated state, or furthermore, the insulator resin layer, the outer conductor and the protective covering resin layer are firmly fixed in an integrated state. In the manufacturing method for a super-extra-fine coaxial cable, the insulator resin layer and the outer conductor are firmly fixed in an integrated state by heat treatment, or the insulator resin layer, the outer conductor and the protective covering resin layer are firmly fixed in an integrated state.