A carbon nano-fiber, particularly twisted carbon nano-fiber such as a carbon
nano-coil,
carbon nano-twist, carbon nano-rope is produced by means of a catalyst CVD method
using carbon-containing gas as a raw material and a catalyst comprising one or
plural components selected from the group consisting of Cr, Mn, Fe, Co, Ni and
oxide thereof and one or plural components selected from the group consisting of
Cu, Al, Si, Ti, V, Nb, Mo, Hf, Ta, W and oxide thereof is used.