A transfer system includes a robot including a hand configured to transfer a substrate, a transfer chamber within which the robot is disposed, a plurality of substrate-storing cassettes disposed side by side on a sidewall of the transfer chamber in a plan view, and a robot control device configured to control an operation of the robot based on teaching information. The robot control device includes an operation controller configured to cause the robot to transfer the substrate to a storage position while slanting a hand centerline toward the robot away from a storage centerline with respect to a first cassette and while superimposing the hand centerline on the storage centerline with respect to a second cassette.