Provided is a manufacturing apparatus for a carbon nanotube, including: at least two electrodes whose tips are opposed to each other, and a power supply that applies a voltage between the two electrodes to generate discharge plasma in a discharge area between the two electrodes. By using a porous carbonaceous material for at least one of the two electrodes, it is possible to provide a manufacturing apparatus and method for a carbon nanotube, which are capable of manufacturing at a low cost the carbon nanotube that is inexpensive and has a further higher purity.