1. A robot system, comprising: a robot body; a camera mounted on the robot body configured to take an image of an object; and a control device for driving the robot body based on a trajectory to an instruction point, which is set in advance, and, when driving the robot body so that the camera moves linearly toward the object in parallel with an optical axis of the camera, taking an image of the object with the camera while the camera is moving linearly, and measuring a position of the object from the taken image.