AUTOMATIC ANALYZER

An automatic analyzer is provided that is capable of quickly responding when an abnormal process occurs, accurately grasping an abnormal state, and reducing frequencies of early abnormality diagnosis and component adjustment or replacement of the automatic analyzer. The automatic analyzer compares data output information with reference data output information, applies a data alarm to an item of the data output information determined to be in an abnormal state, compares system output information with reference system output information, applies a data alarm to an item of a data output information determined to be in an abnormal state, and executes a predictive diagnosis of a failure state of the automatic analyzer based on a temporal change of the data output information obtained by the analyzer using an internal standard substance as a sample and a temporal change of the system output information.