The robot system for which the position of a camera attached to the arm is changeable to multiple positions. The robot system memorizes offset information between the arm and the camera for each of multiple positions. Further, the robot system moves the arm to the position offset by the offset information corresponding to the attachment position of the selected camera. As a result, even when the mounting position of the camera is changed, the robot system can move the camera to an appropriate position when imaging and perform imaging without requiring troublesome teaching.