a digital fluorography apparatus includes an x - ray tube , an x - ray / photo converter , an imaging system , an image processing unit , a display , a comparing unit , a fluorographic control unit , an imaging control unit , and an x - ray tube control unit . the converter opposes the tube to sandwich an object therebetween . an x - ray image formed by the converter is sensed by the imaging system . the image processing unit directly outputs image data sensed by the imaging system in a fluorography mode , and performs predetermined digital image processing of the image data and then outputs the resultant image data in an imaging mode . the image data output from the image processing unit in the fluorography mode is compared with reference data by the comparing unit , and a fluorographic control signal corresponding to the comparison result is generated from the fluorographic control unit . the imaging control unit generates an imaging control signal corresponding to the control data from the fluorographic control unit . the x - ray tube is driven under the x - ray radiation conditions corresponding to the control signals .