A display device includes a first substrate, a second substrate facing the first substrate, first to third electrodes formed on the first substrate, and a fourth electrode formed on the second substrate, wherein the first and second substrates include a main display region and an assistance display region, wherein the first and second electrodes form a horizontal electric field that is substantially parallel to the surfaces of the first and the second insulating substrates, and the third and fourth electrodes form a vertical electric field that is substantially perpendicular to the surfaces of the first and second substrates.