The present invention provides carbon nanotubes perpendicularly and densely deposited over a wide area of a substrate. The carbon nanotubes are manufactured by supplying alternating-current power at a specific frequency between an anode and a cathode disposed in a reactor, and causing plasma to be generated between the anode and the cathode by introducing mixed gas containing an aliphatic hydrocarbon having 1-5 carbon atoms and hydrogen or mixed gas containing an aromatic hydrocarbon and hydrogen. The substrate is disposed between the anode and the cathode and held at a distance two times or less of the mean free path of a hydrocarbon cation from the anode.