An object of the present invention is to provide a new light emitting element with little initial deterioration, and a display device in which initial deterioration is reduced and variation in deterioration over time is reduced by a new method for driving a display device having the light emitting element. One feature of the invention is that a display device comprising a light emitting element including a first electrode, a second electrode opposed to the first electrode, and a mixed layer of metal oxide and an organic compound provided between the first electrode and the second electrode is subjected to aging drive.