According to one embodiment, in an X-ray computed tomography apparatus including a gantry unit including an X-ray tube and an X-ray detector, a bed unit, and a console, the X-ray computed tomography apparatus includes a storage unit, a power supply unit, and a power supply control unit. The storage unit stores examination schedule data of the X-ray computed tomography. The power supply unit selectively operates between an active mode of supplying power to at least one of the gantry unit, the bed unit, and the console and a standby mode of stopping supplying power to at least one of the bed unit and the gantry unit and supplying, to the console, power smaller than power supplied in the active mode. The power supply control unit controls switching from the active mode to the standby mode based on the examination schedule data.