A method for operating a clothes treating apparatus having a dry function capable of reducing abrasion and crease of a dry object and improving a dry efficiency is provided. The method for operating a clothes treating apparatus having a dry function for drying the clothes by supplying hot air into the interior of a tub includes: supplying hot air into the interior of the tub while forwardly and reversely rotating the tub; detecting the moisture content of the clothes put into the interior of the tub; lowering the temperature of hot air and supplying the same when the detected moisture content is less than a first predetermined level; and supplying the hot air having a lower temperature to complete drying.