Abstract: A control apparatus comprises a control stick, a sensor for detecting the angular displacement amount of the stick and outputting a position signal, a spring for generating an operation force in accordance with the angular displacement amount based on a neutral point of the stick, a back drive unit coupled to the stick via the spring, for driving the stick to move the neutral point; and a controlling section for controlling the unit, the unit including a differential gear section having input shafts and an output shaft, a back drive motor coupled to the input shaft, an electromagnetic brake coupled to the input shaft, and an output arm coupled to the output shaft to drive the stick, and when the stick is being moved, the electromagnetic brake is put into disconnection to release the input shaft, the motor is rotated in the reverse direction, thereby preventing the occurrence of a transient.