Provided is a method of controlling adaptive auto exposure. In the method, a digital photograph captured from an object and a background is divided into an object region where the object is mainly located and a background region where the background is mainly located. Average luminances of the object and background regions are calculated, and a luminance difference between the average luminances of the object and background regions is calculated. If the luminance difference is within a predetermined range, an average luminance of the entire photograph is calculated by applying a weight to the average luminance of the object region, and exposure is controlled based on the calculated average luminance of the entire photograph so as to emphasize the object region.