A display device includes a display panel having pixels arranged in a matrix form, a driving circuit for outputting an analog voltage according to a video signal to the pixels through signal lines, a plurality of measuring circuits each for detecting the amount of transmitted light, a single totalizing circuit for totalizing the results of measurements made by the measuring circuits, and a control circuit for adjusting a potential on a common electrode of the display panel in accordance with the result of the totalization from the totalizing circuit. The results of measurements made by the plurality of measuring circuits are totalized by the single totalizing circuit.