A catalyst for manufacturing carbon substances, such as carbon nanotube
that has a diameter of 1000 nm or less, the catalyst containing at least
iron, cobalt or nickel of a first element group and tin or indium of a
second element group. The catalyst can be formed by at least tin and
indium in addition to cobalt or nickel. The former catalyst provides a
2-component type catalyst and a multi-component type catalyst that is
composed on the basis of the 2-component type catalyst, and the later
catalyst provides a 3-component type catalyst and a multi-component type
catalyst that is composed on the basis of the 3-component type catalyst.