Augmented reality (AR) glass is provided. The AR glass includes a first light source which emits display light for displaying an AR image, an eye tracking (ET) sensor for detecting reflected light reflected from the eye of a user, glass, which includes a display waveguide for guiding the display light, emitted from the first light source, to a display area of a see-through display, and an ET waveguide for guiding the reflected light to the ET sensor, and a processor electrically connected to the first light source and the ET sensor, wherein the processor controls the first light source so as to emit the display light, and tracks, through the ET sensor, the gaze of the user on the basis of the detected reflected light.