Abstract: A visual servo system includes a robot that handles an object, an irradiation device that irradiates light onto the object, and a camera that captures an image of the object and outputs a current image. The visual servo system reads, from a storage medium, a target image that is assumed to be captured by the camera when the object is in target position and attitude, and the light irradiated from the irradiation device is striking the object. The visual servo system calculates control input to be inputted to the robot based on a difference in luminance value between the current image and the target image, and inputs the control input to the robot. The light that is irradiated by the irradiation device is light that has a luminance distribution based on a reference image in winch a luminance value changes along a predetermined direction.