A display device includes: a panel including a plurality of pixel circuits, each of the pixel circuits including a light emitting element having one end coupled to a first voltage source for supplying a first voltage and another end coupled to a second voltage source for supplying a second voltage; a controller for reducing image data for one frame and for outputting a control signal and a data signal to display an image corresponding to the reduced image data on the panel; a voltage difference setting unit for detecting a peak value of the reduced image data and for calculating a driving voltage for generating a peak driving current corresponding to the peak value; and a power supply for generating the first and second voltages and for providing the first and second voltages to the panel in accordance with the driving voltage.