To provide a coaxial cable for high frequency retaining good conveying characteristics and fewer manufacturing constraints, and to provide its manufacturing method.

The method of manufacturing the coaxial cable for high frequency 11 is composed of an insulating-core arranging process in which a plurality of insulating-cores 22 having insulating layers 13 formed around outer periphery of central conductors 12 are sent out and arranged parallel to each other, a metal tape pasting process wherein metal tapes 26 including metal layers are pasted to the arranged insulating-cores 22 from both sides of arrangement faces by holding along the shapes of the insulating-cores 22, and a separating process wherein parts of metal tapes 26 themselves stuck together between the insulating-cores 22 are cut off to obtain external conductor cores 43 in which external conductors 14 composed of the metal tapes 26 are formed around the periphery of the insulating layers 13.