Abstract: A state determination device determines the state of a drive mechanism configured to operate while holding a substrate in a substrate processing apparatus. The state determination part includes: an acquisition part configured to acquire operation data for the drive mechanism; a model generation part configured to generate a monitoring model for the drive mechanism by executing machine learning using an auto-encoder based on normal operation data that is derived from the operation data acquired by the acquisition part when the drive mechanism is operating normally; and a first determination part configured to determine the state of the drive mechanism based on first output data obtained by inputting, to the monitoring model, evaluation data that is derived from the operation data acquired by the acquisition part when the drive mechanism is being evaluated.