A display apparatus includes a switching element having a first gate electrode, a source and drain electrode, a channel area formed between the source and drain electrode, and a second gate electrode. The second gate electrode is electrically insulated from the first gate electrode through the channel area, and different control voltages are applied to the second gate electrode according to the control period of the first gate electrode. The different control voltages are applied to the second gate electrode according to the turn on/off states of the switching element for increasing the turn on current in the channel area and for minimizing the turn off (leakage) current in the channel area.