A processing method of a flat panel display apparatus in which a cathode panel having electron emitting regions and an anode panel having phosphor regions and an anode electrode are joined is provided. A predetermined voltage is applied to each electron emitting region, thereby allowing electrons to be emitted therefrom. In a predetermined row, initial electron emitting states in the electron emitting regions are measured. After that, a voltage higher than that of the electron emitting region in a row showing the low initial electron emitting state is applied to the electron emitting region in the row showing the high initial electron emitting state for a predetermined time, thereby performing aging.