A camera includes a display device which has thin film transistors (TFT). A gate insulating film of the TFT has a first insulating film including silicon oxide and a second insulating film including silicon nitride. A third insulating film including silicon nitride is formed over the first and second insulating films and a gate electrode. The third insulating film is in direct contact with an upper surface of an extending portion of the first insulating film and an upper surface of an extending portion of the second insulating film.