A method of realizing selective separation of metallic monolayer carbon nanotubes and semiconductor carbon nanotubes from fascicular carbon nanotubes; and obtaining of metallic monolayer carbon nanotubes separated at high purity through the above method. Metallic monolayer carbon nanotubes are dispersed (raveled) one by one from fascicular carbon nanotubes not only by the use of a difference in interaction with amine between metallic monolayer carbon nanotubes and semiconductor carbon nanotubes due to a difference in electrical properties between metallic monolayer carbon nanotubes and semiconductor carbon nanotubes but also by the use of the fact that an amine is an important factor in SWNTs separation. The thus dispersed carbon nanotubes are subjected to centrifugation, thereby attaining separation from non-dispersed semiconductor carbon nanotubes.