An abnormality diagnosis method that diagnoses abnormality of a braking unit included in a prescribed apparatus that includes: the braking unit including a pressing member, an urging member that urges the pressing member toward an actuator, and an attraction device that releases an urging state of the pressing member that is pressed by the urging member; and a controller configured to control braking by the braking unit and that changes operation programs each including a plurality of operation steps, based on an attraction time period when the pressing member is separated from the actuator to release braking. The abnormality diagnosis method includes: a step of the prescribed apparatus calculating the attraction time period when the prescribed apparatus executes prescribed operation steps associated with corresponding operation programs; and a step of diagnosing abnormality of the braking unit based on the calculated attraction time period.