Disclosed is a display apparatus. The display apparatus includes a mirror display, a sensor, a storage which stores transmission and reflection characteristics information of the mirror display, identify and a processor configured to a threshold and to output an image corresponding to the image signal on the mirror display based on the transmission characteristics information, reflection characteristics information, and an amount of external light sensed through the sensor, to adjust a luminance of a image signal based on whether a grayscale of the image signal is less than or equal to the threshold.