Provided is an apparatus for producing carbon nanotubes. The apparatus includes a reaction chamber and a rotating member. The reaction chamber provides a reaction space in which metal catalysts and a source gas react with one another to produce carbon nanotubes. The rotating member increases fluidizing of the metal catalysts in the reaction space to increase productivity and raise the gas conversion rate, thereby reducing the price of carbon nanotubes and preventing adhering of metal catalysts to the sidewall of the reaction chamber.