A robot system efficiently performing an operation of moving a robot to close to and/or separate from a target point, such as teaching operation. A camera of a visual sensor is mounted to the robot such that a distal end of an end effector is seen within the field of view of the camera, and the end effector's distal end and a target position on an object are specified on a monitor screen. When an approach key is depressed, a target position is detected on an image, and a difference from a position of the end effector's distal end is calculated. Whether the difference is within an allowable range is checked. Depending on the result, an amount of robot motion is calculated, and the robot is operated. The processing is repeated until the depressed approach key is released. When a retreat key is depressed, the robot moves away from the object. The robot may be caused to stop using a distance sensor.