A display device includes a display panel to display an image, a data driver to supply a data signal to the display panel, and a power supply to supply a driving voltage to the display panel through a power supply line and to supply a data driving voltage to the data driver, in which the power supply is configured to detect a voltage of the power supply line during an initial driving period during which the data driving voltage is supplied to the data driver, to supply a ground voltage to the display panel when the voltage detected from the power supply line is different from a reference voltage, and to supply the driving voltage to the power supply line after the initial driving period.