A field emission device (5) includes cathode electrodes (51), emitters
(52) formed on the cathode electrodes, grid electrodes (54) formed over
the cathode electrodes at a distance apart from the emitters, and
isolated films (55) formed on surfaces of the grid electrodes neighboring
the emitters. Preferably, the isolated film has a thickness ranging from
0.1 to 1 microns. The isolated film may be a film made of one or more
insulating materials, such as SiO.sub.2 and Si.sub.3N.sub.4.
Alternatively, the one or more insulating materials can be selected from
a material having a high secondary electron emission coefficient, such as
MgO, Al.sub.2O.sub.3 and ZnO. Additionally, the isolated film can be
further formed on a second surface of the grid electrode distal from the
emitter.