Provided is an equipment diagnostic device that comprises the following: a process data acquisition unit for acquiring process data indicating the state of a process to be executed in a plant; a production data acquisition unit for acquiring pro - duction data indicating the production status in the plant; a state information generation unit for generating state information estimating the operating state of equipment operated in the process on the basis of the acquired process data; and a determination unit for determining the operating state of the equipment on the basis of the acquired process data or the generated state information, and the acquired production data.
