Abstract: A method and apparatus for the continuous production of carbon nanostructures so as to improve their quality and quantity. Such structures have potential application as hydrogen storage means in new energy sources. The carbon nanostructures (20) are grown in a continuous or semi-continuous manner on a continuous, elongate, heated substrate (15) to form a coated substrate the process involving movement of the substrate through one or more deposition chambers (2,3). The substrate may be an electrically heated wire (15).