An electron-emitting device in which the specific capacitance and the
drive voltage are reduced, and which is capable of obtaining a finer
electron beam by controlling the trajectory of emitted electrons. An
electron-emitting portion of an electron-emitting member is positioned
between the height of a gate and the height of an anode. When the
distance between the gate and a cathode is d; the potential difference at
driving the device is V1; the distance between the anode and the
substrate is H; and the potential difference between the anode and the
cathode is V2, then the electric field E1=V1/d during driving is
configured to be within the range from 1 to 50 times E2=V2/H.