Electrically conductive diamond-like amorphous carbon (DAC) films with nitrogen (DAC:N) were deposited, and studied with respect to their potential application to field emitters. In the deposition of electrically conductive DAC:N films, a supermagnetron plasma CVD apparatus with multi-function was used. By using the supermagnetron plasma CVD apparatus, hard and thick DAC:N films of very low electrical-resistivity (0.034 Ωcm) were deposited. Cone-shaped Si field emitters were fabricated, and the surfaces were coated with 50 nm-thick DAC:N films. Characteristics of the emitters revealed that large reductions of turn-on voltage were achieved by the coating.