A technique relating to an apparatus abnormality diagnosis system, capable of easily creating and adding/updating an diagnosis model with respect to an initial and new failure case, and appropriately and efficiently achieving diagnosis of abnormality and instruction of operation using the model. In the abnormality diagnosis system, an diagnosis model creating process unit creates a structured abnormality model expressing a structured abnormality of maintenance operation type to an alarm and apparatus event relating to the maintenance operation type by a graph network structure based on acquisition of maintenance operation data. And, by synthesizing the structured abnormality model with an existing structured abnormality model, the diagnosis model is updated.