An X-ray CT photographic apparatus 1 includes: a beam shaping mechanism 13 that is configured to regulate an irradiation range of an X-ray generated from an X-ray generator 10a and shapes the X-ray into an X-ray cone beam BX and a main body controller 60 that is configured to change a read region, where an X-ray detection signal is read in the X-ray detector 21, according to the irradiation range of the X-ray cone beam BX. The main body controller 60 is configured to change the irradiation range of the X-ray cone beam BX to an x-axis direction during X-ray CT photography such that only a setting CT photographic region CA is irradiated with the X-ray cone beam BX according to the setting CT photographic region CA input through a CT photographic region setting unit (200, 200A to 200D, 300). The main body controller 60 that acts as a read region controller is configured to change a read region in an X-ray detector 21 with respect to the x-axis direction in a detection surface 21 of the X-ray detector 21 during the X-ray CT photography.
