Electron emission device and electron microscope

Abstract

An electron emission device having a narrow electron energy range and excellent electron emitting efficiency, and an electron microscope using the electron emission device. An electron emission device having a laminated structure in which a first electrode, an electron accelerating layer made of an insulating film, and a second electrode are laminated in this order, in which the second electrode through which electrons transmit and from whose surface electrons emit, and the energy width of the emitted electrons is 100 meV or more and 600 meV or less. For example, graphene having one or more layers and 20 layers or less can be used as the second electrode, and hexagonal boron nitride can be used as the insulating film.

Dependencies are inferred from the claim text.