A 300-nm-thick diamondlike carbon (DLC) film was deposited on to a heavily doped n-type Si (111) wafer by filtered are deposition. A flat thin film cylindrical emitter array was then fabricated by reactive-ion etching the DLC film. Its electron field emission properties were studied using a simple diode structure. A field emission current of 0.1 mu A was detected under an electric field of 5.2 V/mu m. As large as 64.1 mA/cm(2) of field emission current density was achieved after an activation process under a 39 V/mu m field. An image formed on the anode screen showed that electron field emission from the DLC flat emitter array is rather uniform. The field emission behavior is also consistent with Fowler-Nordheim theory. Hydrogen plasma surface treatments were found to enhance the field emission properties.