A robot system includes a robot including a first hand, a second hand, an arm mechanism, and an elevator. The first hand is to hold a substrate. The second hand is to hold the substrate. The arm mechanism supports the first hand and the second hand to provide a height difference between the first hand and the second hand in a height direction of the robot. The elevator is to move the arm mechanism in the height direction within a moving range larger than the height difference. Both the first hand and the second hand put the substrate in the holder. Circuitry is configured to control the robot to move the arm mechanism in the height direction by the elevator to pass the substrate from the first hand to the second hand via the holder.