An electron emission device comprising an electron emission element (1)
having a lower electrode (2), an upper electrode (5) consisting of a thin
film, the surface of the upper electrode (5) being exposed to external
space, and a semiconductor layer (4) formed between the lower electrode
and the upper electrode, a counter electrode (21) provided to face the
upper electrode (5) across the external space, a fine particle charging
voltage control unit (22) for applying a voltage that charges fine
particles deposited on the surface of the upper electrode (5) to between
the upper electrode (5) and the lower electrode (2), and flying voltage
control unit (23) for applying a voltage that sends charged fine
particles flying from the surface of the upper electrode (5) to between
the upper electrode (5) and the counter electrode (21), wherein the fine
particle charging voltage control unit is operated to charge deposited
fine particles, and the flying voltage control unit is operated to sent
charged fine particles flying toward the counter electrode (21).