Substrate processing apparatus and substrate processing method

A substrate processing apparatus according to an aspect of the present disclosure includes a substrate processing unit, a substrate transfer unit, a first detection unit, a second detection unit, and a third detection unit. The substrate processing unit holds and processes a substrate. The substrate transfer unit has a rotational axis and carries the substrate in the substrate processing unit. The first detection unit detects a position of the substrate transfer unit relative to the substrate processing unit in a direction of travel thereof when the substrate is carried in the substrate processing unit in the direction of travel. The second detection unit detects a position of the substrate transfer unit relative to the substrate processing unit in a direction that is perpendicular to the direction of travel. The third detection unit detects an inclination of the rotational axis of the substrate transfer unit relative to the substrate processing unit.