A process makes at least one nanotube between two electrically conducting elements located on a substrate, using, inside a deposition chamber, a microwave power, a magnetic field, and at least one electronic cyclotron resonance zone faciliting ionization and/or dissociation of a gas containing carbon injected into the deposition chamber at a low pressure inside the deposition chamber, causing ionization and/or dissociation of this gas in each electronic cyclotron resonance zone. The ions and electrons produced are located along the field lines of the magnetic field set up in the deposition chamber. The process also includes a screening operation of the various species produced in each electronic cyclotron resonance zone to enable exclusive access of CxHy.sup..degree.non condensable free radicals produced to access a deposition zone adjacent to at least one part of the substrate including the two electrically conducting elements to make the nanotube.