A nanotube-based flexible field effect transistor and its method of manufacture is provided. The field effect transistor according to the invention comprises at least two contact electrodes, respectively drain and source electrodes, an electrical conduction zone connected to the contact electrodes, said zone comprising a plurality of single-wall carbon nanotubes that are substantially aligned, a gate electrode for controlling the electric current circulating in said zone and a flexible substrate on which the contact and gate electrodes are deposited. The nanotube density in the conduction zone is strictly greater than 10 nanotubes per micrometer.