Low-cost electron emission device and field emission display using a cold cathode electron source having a high electron beam utilization efficiency and capable of controlling the spread of the electron beam. Under the condition EaEg, the electric field strength near the gate electrode forming an electron emission control unit is varied between a central portion and a peripheral portion in the plane of a single pixel (or sub-pixel), thereby controlling the spread of the electron beam. A device using a field emission-type electron source array capable of achieving a high emission current density at low voltage can be realized at low cost.