1. A gesture-tracking apparatus comprising: a positioning unit to position a user to appear in an inputted image and to position a first and second predetermined region with reference to the positioned user; and a target-tracking unit to track a first body part existing in the first predetermined region of the user in the inputted image, wherein the target-tracking unit comprises: a laser-beam-generation unit to generate a laser beam; a laser control unit to control the laser-beam generation unit to scan the first body part; and a path-modification unit to modify a path of the laser beam so that the laser beam is directed to the first body part, and wherein the laser control unit is adapted to control the path of the laser beam away from the second predetermined region, if when tracking the first body part the path of the laser beam is directed to the second predetermined region which includes a second body part.