A rotor is rotatably supported in a gantry housing having a substantially sealed structure. An X-ray tube is provided in the rotor. A cooler is provided in the rotor and cools a refrigerant within the X-ray tube. An X-ray detector is provided in the rotor. A reconstruction unit reconstructs an image ON the basis of an output of the X-ray detector. A radiator is fixed inside the gantry housing at a position opposite to an exhaust opening of the cooler when the rotor is stationary.
