An automatic focus adjusting apparatus is provided with a light sensor producing a photoelectric output corresponding to the optical image of an imaged object, an operation device generating control information indicative of the in-focus position of a phototaking lens with respect to the object in response to the photoelectric output, a servo circuit for driving the phototaking lens in response to the control information, and filter means for transmitting the control information of the operation device to the servo circuit and controlling the responsiveness of the servo circuit to the control information.