A sample image obtaining section repetitively obtains a sample image generated by photographing a given sample by a photographing unit. A feature quantity extracting section generates feature quantity data corresponding to the sample image, in reference to the sample image. The feature quantity extracting section classifies each of a plurality of pieces of feature quantity data into either training data or evaluation data. An evaluation learning section performs learning of an evaluation discriminator by using a plurality of pieces of the training data. A photographing necessity/unnecessity determining section determines necessity/unnecessity of additional photographing of the sample by using the evaluation discriminator in which the learning using the plurality of pieces of the training data has already been performed and a plurality of pieces of the evaluation data. A notifying section gives a notification regarding a result of the determination of the necessity/unnecessity of additional photographing of the sample.