PURPOSE: To provide an X-ray CT device in which a cooler can be arranged on a frame fixing part side by arranging the cooler to cool an X-ray tube on the frame fixing part side, constituting the device of a rotary member and a fixing member in contact with each other and circulating a cooling medium between the X-ray tube and the cooler via a pipeline with which a contact part slides when it is rotated.

CONSTITUTION: A stator 5 and a rotor 6 are set rotatably in a frame by a bearing 13, and a counter ring 10 is mounted on the rotor 6, and the pipeline 15 is formed by bringing the ring 10 into contact with the seal 9 of the stator 5. The other end of a pipe 17 connected to the seal 9 is connected to the oil feeding part of the cooler 2, and the other end of a pipe 12 connected to the ring 10 is connected to the oil receiving part of the X-ray tube 1. Moreover, the pipeline 14 is formed by mounting a counter ring 7 on the stator 5, and bringing the ring 7 into contact with the seal 8 of the rotor 5. The other end of a pipe 11 connected to the seal 8 is connected to the oil discharge part of the X-ray tube 1, and the other end of a pipe 16 connected to the counter ring 7 is connected to the oil receiving part of the cooler 2.