A gantry according to an embodiment includes a rotating frame, a fixing mechanism, and an air sending mechanism. The rotating frame includes an X-ray tube and an X-ray detector configured to detect X-rays emitted from the X-ray tube. The fixing mechanism is configured to support the rotating frame so as to be rotatable on a rotation axis. The air sending mechanism is installed on a lateral face on the outer circumferential side of the rotating frame with respect to the rotation axis and is configured to send air sucked in from the exterior of the rotating frame to the rotation axis side of the rotating frame. The air sending mechanism is installed so as to be offset from the rotating frame.
