1. A defect judging device that judges a presence/absence of a defect in an inspection subject based on detected-image data obtained by a radiographic device provided with a radiation source that irradiates the inspection subject with radiation and an imaging device that obtains the detected-image data by detecting the 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 the 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 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, wherein the position identifying portion uses a product-feature image indicated by the feature data as a template, compares the product-feature image being moved, rotated, and enlarged/shrunk with a detected image indicated by the detected-image data so as to identify a position of a product feature in the detected-image data, and based on the comparison result, identifies the position of the feature site on the imaging device included in the radiographic device.