An organic electroluminescent (EL) display device has a touch panel function and includes a display panel that has first and second light sources disposed along sides of the display portion and first and second light detecting portions disposed on sides of the display portion opposite the light sources. The display device includes a plurality of organic EL display elements disposed in a matrix on the display portion and a plurality of organic EL light source elements disposed in a row in each of the light source portions. The light detecting portions include a plurality of detection light sensors and a reference light sensor disposed in a row in each of the light detecting portions. The display device also includes a comparator that compares an output of the detection light sensors with the output of the reference light sensor.