Nonhydrogenated amorphous carbon films have been prepared by filtered are deposition (FAD), which provides carbon ions with optimum kinetic energies at practical deposition rates. It was found that the carbon atoms were so highly tetrahedrally bonded that the films were referred to as amorphous diamond (alpha-D). The field emission behaviour of the alpha-D films has been studied for the first time. The field emission current more that 10 mu A was detected at an electric field intensity of 18 V/mu m. Such a low threshold field provides the designer of flat panel displays with an opportunity to develop a planar emitter, rather than the conventional Spindt-tip field emitter which requires lithographic and microstructural burdens.