This paper presents the control of an aerial manipulator composed of a quadrotor and a manipulator with two degrees of freedom (2 DOF). There is a strong physical coupling between the dynamics of the UAV and the manipulator arm. This coupling along with external perturbations (e.g. wind gusts), considerably affects the stability of the drone's motion in flight which, consequently, affects the desired accuracy of the end effector with respect to its final task. The solution presented here is based on super-twisting sliding mode control with adaptive gain. It is a continuation of previous study on sliding mode control with adaptive gain [1]. The effectiveness of the controller and its robustness against perturbations are verified and analyzed using numerical simulation.