The invention concerns a field emission device comprising at least a planar cathode (1) made of conductive material with low electronic affinity located on one face (20) of a substrate (2) bearing a dielectric material layer (4) having at least a cavity (40) wherein is located the cathode. A grid made of conductive material (5) is located on the dielectric layer (4), and has an opening (50) centred relative to the cavity (40). The conductive material with low electronic affinity is a material deposited in amorphous form. The invention concerns different embodiments and manufacturing methods. The invention is applicable to electronic guns and display devices.
