A display device in which characteristic change of an organic light emitting layer due to deterioration or temperature change can be detected to keep the constant luminance of a light emitting element is provided. A monitor region is provided in addition to a pixel portion for display. A plurality of monitor elements is arranged in the monitor region. A switching circuit is provided so as to prevent a large amount of current from flowing in a shorted monitor element among the plurality of monitor elements. As a result, by monitoring potential change between electrodes of the monitor element, the voltage or the current that is supplied to a light emitting element in the pixel portion for display can be corrected in accordance with time degradation or temperature change.