A substrate transfer robot includes a hand and a controller. The hand includes at least one detector configured to detect an arrangement state of a substrate in a substrate storage. The controller is configured to control the at least one detector to detect the arrangement state of the substrate in the substrate storage with the hand inclined in plan view toward a rotation center of the substrate transfer robot relative to a substrate storage center line. The substrate storage center line is in a direction perpendicular to a front surface of the substrate storage.