A control unit acquires first radiographic image data and second radiographic image data and derives bone density from an image of a derivation region of a DXA image which is a difference image between a first radiographic image and a second radiographic image. Then, the control unit derives an evaluation value of the accuracy of derivation of the bone density, on the basis of at least one of the first radiographic image, the second radiographic image, and a bone part ES image, a soft part ES image, and a DXA image which are generated using the first radiographic image and the second radiographic image.