To provide a super-extra-fine copper-alloy wire having excellent tensile strength, wire drawability and bendability, a copper-alloy stranded-wire conductor, extra-fine coaxial cable, and a method for manufacturing the super-extra- fine copper-alloy wire.

The super-extra-fine copper-alloy wire can be obtained by preparing a wire rod where Ag of ≥99.99 mass% purity is added in amounts of 1.0-5.0 mass% to high-purity Cu containing ≤1 mass ppm, in total, of inevitable impurities and subjecting the wire rod to wire drawing to ≤0.08 mm diameter. Excellent wire drawability and bendability can be provided because the foreign matter causing wire breakage contained in a matrix can be minimized, and also excellent tensile strength can be provided because Ag is used as an additive element.