1. A defect judging device that judges the presence/absence of a defect in an inspection subject based on detected-image data obtained by a radiographic device that detects radiation that has passed through the inspection subject, the defect judging device comprising: a position identifying portion for identifying a position of a feature site in the detected-image data based on a shape of the feature site of the inspection subject indicated by feature data that are stored in a storage portion in advance; and a defect judging portion for extracting a defect candidate with reference to the feature site in the detected-image data identified by the position identifying portion and of judging the presence/absence of a defect in the inspection subject based on a characteristic quantity of a defect indicated by defect characteristic data stored in the storage portion in advance and a characteristic quantity of the defect candidate.