A robot system includes a robot, a vision sensor, a target position generation circuit, an estimation circuit, and a control circuit. The robot includes an end effector and is configured to work via the end effector on a workpiece which is disposed at a relative position and which is relatively movable with respect to the end effector. The vision sensor is configured to take an image of the workpiece. The target position generation circuit is configured to, based on the image, generate a target position of the end effector at every generation interval. The estimation circuit is configured to, at least based on relative position information related to the relative position, estimate a change amount in the relative position at every estimation interval. The control circuit is configured to control the robot to move the end effector based on the target position and the change amount.