Fins are arranged on the rotating side of an X-ray computed tomography apparatus. The fins are rotated to generate airflow as the rotating side is rotated. This airflow serves to discharge wear debris to the outside of the X-ray CT apparatus, thereby preventing the wear debris from scattering toward an X-ray tube and support bearing. In consequence, in the X-ray CT apparatus provided with a slip ring, the wear debris produced in a contact space between the slip ring and a brush can be prevented from being scattered in the apparatus.