An X-ray imaging apparatus implements a fluoroscopy that irradiates a weaker dose of X-rays than a dose on the long-length imaging toward a subject M at each location in the long-length imaging range, while moving an X-ray tube in a body axis direction relative to the subject M prior to the long-length imaging, when the long-length imaging is implemented by moving the X-ray tube 2 in the body axis direction relative to the subject M. The dose D1 at the location having the thick body thickness is less, so that the tube voltage is set up to be high as the tube voltage V1 and vice versa, the dose D2 at the location having the thin body thickness is high, so that the tube voltage is set up to be low as the tube voltage V2. The tube voltage is set up to implement a long-length imaging so that doses of X-rays that transmit the subject coincide with each other at each location based on the X-ray dose that transmits the subject M on the fluoroscopy, so that the imaging condition relative to the long-length imaging in the region in which the height (body thickness) of the subject is different from each other can be set up appropriately.
