An object of the present invention is to provide a display device for making it possible to accurately adjust a gradation current even if there is a variation in characteristics of a transistor for driving an organic EL element in a display device using an organic EL element. The following are included: a current detecting circuit for detecting a current circulating through a light emitting element, a current adjustment control circuit for comparing the detected current value with a reference current value and adjusting a current to be supplied to the light emitting element of a display portion in accordance with the comparison result, and a reference current circuit for generating a reference current correspondingly to the adjusted current. Moreover, a reference current circuit is formed on the substrate same as the substrate on which a light emitting element of a display portion is formed. Thereby, the variation of transistor devices constituting the reference current circuit is corrected and the reference current can be adjusted at a high accuracy.