TWI762101B

To provide an abnormality diagnostic apparatus which can precisely determine a state of a diagnosis object device.SOLUTION: An abnormality diagnostic apparatus 100 includes: a failure mode selection unit 106 for selecting a failure mode to be detected; a teacher data generating unit 103 for generating teacher data DT for determining, based on failure detection measurement data that is data corresponding to the failure mode of a diagnosis target apparatus 10 or another apparatus, whether or not the diagnosis target apparatus 10 has any failure; a measurement item importance calculating unit 104 for calculating importance of measurement items in the failure mode based on the teacher data DT; a feature amount selecting unit 105 for selecting a part of the measurement items as a feature amount for the failure mode based on the calculated importance; an abnormality degree calculating unit 107 for calculating an abnormality degree A corresponding to the failure mode based on measurement data relating to the feature