Abstract: A control device for a power shovel having a first boom, a second boom and an arm rotatable around the longitudinal axis of the arm, detects the angle of the arm with respect to the horizontal plane based on the posture angles of the first and second booms and the arm, and controls the arm cylinder such that the angle of the arm with respect to the horizontal plane is held to a reference angle. Further, the control device detects a deviation angle between the current direction and the initial directions and controls the revolution angle of the arm so as to make the deviation angle zero. Furthermore, the control device designates a moving direction of the connection point between the second boom and the arm along a plane including the first boom, the second boom and the arm, and controls cylinders for the booms such that their connection point may be moved in the moving direction thus designated.