1. An apparatus capable of detecting hands of a subject in real time, the apparatus comprising: a first image input part configured to generate a first image photographed at a first side with respect to the subject; a second image input part configured to generate a second image photographed at second side with respect to the subject; a stereoscopic processor configured to generate a distance image indicating three-dimensional distance information by comparison information of the first image and the second image; a skin region detector configured to determine whether each pixel within any one of the first and second images is a skin pixel and generate a skin image indicating whether each pixel within any one of the first and second images is a skin pixel; a skin/distance pixel combiner configured to generate a combined image by combining the distance image with the skin image in units of pixels; a background and noise eliminator configured to generate an effective image including two or more hand candidate regions by eliminating background and noise from the combined image; a hand correlation determiner configured to calculate effective values with respect to respective pairs of the hand candidate regions which can be combined within the effective image and determine a pair of hand candidate regions having largest effective values as hand regions; a hand candidate region detector configured to generate a hand candidate image from which the hand candidate regions are detected; and an erosion image generator configured to determine a number of erosion operations which are to be repeatedly performed to eliminate pixels corresponding to an expected thickness of a finger within the hand candidate image, with reference to a table which defines the number of erosion operations according to a distance value of a hand and generate an erosion image by repeatedly performing the number of erosion operations.