A radiography apparatus with a function for evaluating image quality is provided. To accomplish this, the radiography apparatus includes a radiating-generating unit for emitting radiation, an imaging unit for converting the radiation into image data, a measuring unit for measuring an image-quality evaluating value of the image data, and a determining unit for determining the image quality of the imaging unit based on a plurality of image-quality evaluating values of the image data acquired at a plurality of points in time, where each image-quality evaluating value corresponds to the image data acquired at one of the points in time.