A robot system, including an arm capable of controlling a position and orientation of an arm tip portion, a hand, which is attached to the arm tip portion and which includes a grasping mechanism configured to grasp an operation target, capable of controlling a relative position and orientation from the arm tip portion of the grasped operation target, and a position and orientation measurement apparatus configured to perform relative position and orientation measurement from the arm tip portion of the grasped operation target, wherein measurement of the relative position and orientation from the arm tip portion of the operation target is performed after the operation target is grasped by the grasping mechanism, while the arm tip portion is still moving, and correction of the relative position and orientation from the arm tip portion of the hand is performed based on a result of the position and orientation measurement so that the arm tip portion takes a predetermined relative position and orientation from the arm tip portion.