A display device capable of applying reverse driving voltage for a light
emitting element to a light emitting element every certain period for
prolonging light emitting element's life and burning out a shorted
portion. Besides a path for supplying forward current to the light
emitting element, a path for supplying reverse current is provided. A
driving transistor is provided in the former path while a transistor (AC
transistor) is provided in the latter path, thereby a switching between
the two paths is controlled. The AC transistor has a rate L/W of a
channel length L to a channel width W smaller than that of the driving
transistor. Accordingly, current flowing into the light emitting element
can flow into the AC transistor in the case of reverse driving voltage
being applied to the light emitting element.