According to one embodiment, an X-ray CT apparatus includes a gantry, storage circuitry and control circuitry. The gantry including an X-ray tube is relatively movable on a floor surface of an examination room. The storage circuitry store information of a first boundary indicating an outer edge of a FOV inside the opening portion and information of a second boundary located between the first boundary and an inner surface of the opening portion to prevent interference between an object and the gantry. The control circuitry control the X-ray tube to stop emitting X-rays based on a relative positional relationship between a scan target area of the object and the first boundary or control the gantry to stop moving based on a relative positional relationship between a non-scan target area of the object and the second boundary.
