In an X-ray Computed Tomography apparatus according to an embodiment, an angle determining unit determines an angle indicating a position of an X-ray radiation unit in a circular orbit at a moment to start radiation after a return of reciprocation, based on a time from a moment of completion of radiation in a movement to a certain direction until a moment to start radiation in a movement after the return, which is a time calculated from scanning conditions. A radiation control unit controls radiation by the X-ray radiation unit so as to start in accordance with the angle determined by the angle determining unit.
