An unmanned aerial vehicle including a body part having an inner space filled with light gas; and a plurality of wing parts mounted on the body part and providing a propelling force. Each of the wing parts includes a fin part having a first rib and a second rib, a first servomotor and a second servomotor connected to one end of the first rib and one end of the second rib, respectively, to move the other end of the first rib and the other end of the second rib in a control angle range; a control unit for controlling the first servomotor and the second servomotor to make the first rib and the second rib move while having a particular phase difference therebetween; and a third servomotor connected to the first servomotor and the second servomotor to rotate the fin part to determine the propelling direction of the body part.