A field emission backlight unit for a liquid crystal display (LCD) includes: a lower substrate; first electrodes and second electrodes alternately formed in parallel lines on the lower substrate; emitters disposed on at least the first electrodes; an upper substrate spaced apart from the lower substrate by a predetermined distance such that the upper and lower substrates face each other; a third electrode formed on a bottom surface of the upper substrate; and a fluorescent layer formed on the third electrode. Since the backlight unit has a triode-type field emission structure, field emission is very stable. Since the first electrodes and the second electrodes are formed in the same plane, brightness uniformity is improved and manufacturing processes are simplified. If the emitters are disposed on both the first electrodes and the second electrodes, and a cathode voltage and a gate voltage are alternately applied to the first electrodes and second electrodes, the lifespan and brightness of the emitters can be improved. The above advantages are also achieved as a result of the method of driving the backlight unit and the method of manufacturing the lower panel thereof.