In an electron-emitting device having a pair of electroconductors arranged
on a substrate at an interval, a top of one electroconductor is higher
than that of the other electroconductor and a groove extending from the
interval region toward a position under a region where the one
electroconductor is come into contact with the substrate is formed on the
substrate. Deterioration of the electron-emitting device due to collision
of charged particles is suppressed by the asymmetrical electron-emitting
region, electron-emitting efficiency is improved, and a long life is
realized.