To implement brightness change of pixels due to variations in environmental temperatures with low electric power, the display device includes a display part having a display area arrayed with plural pixels, a display scanning circuit and a signal driving circuit for driving the plural pixels, and a power circuit that supplies a current for illuminating each of the plural pixels with brightness corresponding to a display signal from the signal driving circuit; and a detection unit that includes: a monitor element for driving a constant current that detects environmental temperatures; and plural constant current sources, detects a voltage value relating to the luminous intensity of the pixels by the monitor element to generate a signal to control an output voltage of the power circuit, and changes over a constant current source of the monitor element according to a voltage value detected in the detection unit.