A carbon nanotube device has a substrate (1), a layer (3) having a space (5) which penetrates in the vertical direction of the substrate (1), and carbon nanotubes (7) formed on the surface of the substrate facing the space (5) in such a manner as to have number density distributions successively changed according to the distances from the center of the space (5), the supply amount of catalyst substances is diluted by supplying the catalyst substances through an opening of a coating film (4) opposite to the substrate (1) and the hole (5), a catalyst having a nominal thickness distribution according to the way how the space (5) appears is formed on the substrate (1) facing the space (5), and a carbon source is supplied, thereby forming carbon nanotubes having the number density distribution are formed on the substrate (1).