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 Ea≧Eg, 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.