An abnormality diagnosis method of diagnosing, with an abnormality diagnosis apparatus, abnormality of a braking unit included in a prescribed apparatus, the prescribed apparatus including: 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, the prescribed apparatus being configured to change between a plurality of operation programs with each operation program including a plurality of operation steps, the abnormality diagnosis method comprising: calculating, by the abnormality diagnosis apparatus, an attraction time period when each of the operation steps in each of the operation programs is executed each time the prescribed apparatus repeats each of the operation steps in each of the operation programs, the attraction time period being a breaking release period; calculating, by the abnormality diagnosis apparatus, an evaluation value for evaluating accuracy of the calculated attraction time period for each of the operation steps in each of the operation programs; wherein calculating, by the abnormality diagnosis apparatus, the evaluation values of the attraction time periods is based on a variance of the calculated attraction time periods and on a normal ratio of normal attraction time periods to all the calculated attraction time periods; wherein the method comprises comparing a calculated attraction time period with a preset attraction time period at the normal state, and when a difference therebetween is equal to or less than a specified threshold, determining that the attraction time period is a normal value; and wherein the method comprises calculating the normal ratio of normal attraction time periods such that the normal ratio = the number of normal attraction time periods / the number of all the attraction time periods x 100; the method further comprising associating, by the abnormality diagnosis apparatus, as a prescribed operation step, the operation step with the highest evaluation value, among the calculated evaluation values in each of the operation steps included in each of the operation programs, with the corresponding operation program; calculating, by the abnormality diagnosis apparatus, the attraction time period when the prescribed apparatus executes prescribed operation steps associated with corresponding operation programs; and diagnosing, by the abnormality diagnosis apparatus, abnormality of the braking unit based on the calculated attraction time period of the prescribed operation steps. calculating, by the abnormality diagnosis apparatus, an attraction time period when each of the operation steps in each of the operation programs is executed each time the prescribed apparatus repeats each of the operation steps in each of the operation programs, the attraction time period being a breaking release period; calculating, by the abnormality diagnosis apparatus, an evaluation value for evaluating accuracy of the calculated attraction time period for each of the operation steps in each of the operation programs; wherein calculating, by the abnormality diagnosis apparatus, the evaluation values of the attraction time periods is based on a variance of the calculated attraction time periods and on a normal ratio of normal attraction time periods to all the calculated attraction time periods; wherein the method comprises comparing a calculated attraction time period with a preset attraction time period at the normal state, and when a difference therebetween is equal to or less than a specified threshold, determining that the attraction time period is a normal value; and wherein the method comprises calculating the normal ratio of normal attraction time periods such that the normal ratio = the number of normal attraction time periods / the number of all the attraction time periods x 100; the method further comprising associating, by the abnormality diagnosis apparatus, as a prescribed operation step, the operation step with the highest evaluation value, among the calculated evaluation values in each of the operation steps included in each of the operation programs, with the corresponding operation program; calculating, by the abnormality diagnosis apparatus, the attraction time period when the prescribed apparatus executes prescribed operation steps associated with corresponding operation programs; and diagnosing, by the abnormality diagnosis apparatus, abnormality of the braking unit based on the calculated attraction time period of the prescribed operation steps.