According to this radiography device, by taking images in rapid succession while appropriately obtaining the timing for which an X-ray tube in a rest state should be activated, rapid successive imaging and protection of a radioactive source can both be achieved. That is, in the configuration of the present invention, a time difference is calculated, obtained by subtracting a temporal width of an activation period from a temporal width of an undetectable period, and the time after the time difference has elapsed from the time at which an X-ray is irradiated is determined as the timing for activating the X-ray tube. The temporal width of an undetectable period is the temporal width between the time at which an FPD detects an X-ray once and the time at which the following X-ray can be detected, and the temporal width of an activation period is the temporal width between the start of activation of the X-ray tube to the completion of activation. Thus, while simultaneously activating the X-ray tube and preparing the detector, images can be taken in rapid succession without excessive burden on the X-ray tube and the life of the X-ray tube can be extended.