Thin films of nitrogen doped and undoped amorphous carbon were investigated for their application as field emission cathode;materials. Field emitter films based on amorphous carbon (a-C) were deposited by sputtering of graphite employing an electron cyclotron resonance plasma as argon ion source. The a-C films with a nitrogen content of 0.6 at. % showed the best vacuum electronic properties. Field emission of electrons started at macroscopic electrical fields as low as 3.2 V mu m (current density 1 X 10(-5) mA/mm(2)) and current densities up to 0.6 mA/mm(2) were achieved at an electrical field of 5.8 V/mu m. To locate the emission sites the excitation of a low voltage phosphor (ZnO:Zn) was monitored by a CCD camera. The film resistivity of the a-C films is in the range of 0.1-1 Ohm cm. As revealed by nanoindentation measurements the microhardness is 10-15 GPa indicating a relatively low sp(3) content compared to tetrahedral amorphous carbon (ta-C) films.