An x-ray diagnosing apparatus includes a holding unit including an x-ray source, an x-ray image detector, an a rotating/driving unit for integrally rotating the x-ray source and the x-ray image detector about first, second, and third axes which are perpendicular to each other, sensors for detecting rotational angles with respect to the first, second, and third axes, respectively, calculating unit for calculating clinically defined diagnostic angles by using the rotational angles detected by the detectors with respect to the first, second, and third axes, a memory for storing the diagnostic angles calculated by the calculating unit, and a control system for performing write control to write the diagnostic angles, of the holding unit in a photographing operation, in the memory, performing read control to read out the diagnostic angles from the memory in a re-photographing operation, and performing control to supply a command to the rotating/driving unit to set the holding unit in the same state as the photographing operation by using the diagnostic angles read out by the read control.