1. An iris scanning apparatus for identifying a subject, the apparatus comprising: a light source for radiating infrared light toward an eye of a subject; a narrow angle image collector for collecting a narrow image of the eye radiated by the light source; a wide angle image collector for collecting a wide image of an overall face including the narrow image; an image display for displaying the narrow image collected by the narrow angle image collector and the wide image collected by the wide angle image collector; an image processor for determining whether an eye exists in the collected images, and performing, when an eye is determined to exist, iris scanning with the collected image of the eye; and a distance measurer for measuring a distance to the eye, wherein the narrow angle image collector comprises a stereo camera for collecting the narrow images, and wherein the distance measurer match the narrow images collected by the stereo camera to calculate the distance to the eye.