We have studied the field emission characteristics of diamond-like-carbon (DLC) films deposited by a layer-by-layer technique using plasma enhanced chemical vapor deposition, in which the deposition of a thin layer of DLC and a CF4 plasma exposure on its surface were carried out alternatively. The hydrogen-free DLC can be deposited by CF4 plasma exposure for 140 s on a 5 nm DLC layer and show!, an enhanced electron emitting behavior. N-2 gas-phase doping in the CH4 plasma was also carried out to reduce the work function of DLC. The optimum [N-2]/[CH4] flow rate ratio was found to be 9% for the efficient electron emission, at which the onset-Acid was 7.2 V/mu m. It was found that the hydrogen-free DLC has a very stable electron emitting property.