A carbon fiber having catalytic metal supported thereon according to the present
invention is a carbon fiber in which a number of hexagonal carbon layers in the
shape of a cup having no bottom are stacked. At least part of edges of the hexagonal
carbon layers is exposed at an outer surface or inner surface of the carbon fiber.
Catalytic metal is supported on the exposed edges of the hexagonal carbon layers.
The edges of the hexagonal carbon layers are further exposed by removing a deposited
layer formed on the outer surface or inner surface of the carbon fiber. The exposed
edges of the hexagonal carbon layers have an extremely high activity and are suitable
as a support for catalytic metal.