To provide an electron-emitting device that can be used to manufacture an
image forming apparatus having a superior display quality and in which
the development of the abnormal light emission point is suppressed and
the unevenness of brightness is not caused. The electron-emitting device
includes: a cathode electrode and a gate electrode, which are formed on a
base surface and opposed to each other with a space therebetween; and an
electron-emitting film which is located on the cathode electrode, and in
the electron-emitting device, the electron-emitting film has two end
portions (A and B) in a plane substantially parallel to the base surface
in a direction substantially perpendicular to a direction along which the
cathode electrode and the gate electrode are opposed to each other, and a
structure is used in which electric field strengths applied between each
of the two end portions (A and B) of the electron-emitting film and the
gate electrode are made weaker than an electric field strength applied
between a region between the two end portions (A and B) of the
electron-emitting film and the gate electrode at a time of driving.