Field emission-type electron source and method of producing the same

A field emission-type electron source including an insulative substrate and an electron source element formed on the side of one surface of said insulative substrate, said electron source element having:

• a lower electrode;
• a surface electrode;
• and
• a strong-field drift layer including polycrystalline silicon and disposed between said lower electrode and said surface electrode, said strong-field drift layer allowing electrons to pass therethrough according to an electric field generated when a certain voltage is applied to said lower and surface electrodes in such a manner that said surface electrode has a higher potential than that of said lower electrode, said field emission-type electron source comprising:
• a buffer layer provided between said strong-field drift layer and said lower layer, said buffer layer having an electrical resistance greater than that of said polycrystalline silicon.