PURPOSE: To emit generated heat outside with good efficiency by forming the opposite part to a target to be subjected to the radiation heat from an anode while providing its outside with an X-ray shielding body of a protective type container to house an X-ray tube.

CONSTITUTION: An X-ray tube 20, in which a rotary anode 22 and a cathode 23 are oppositely arranged, is housed into a protective type container 10 filled with insulating oil for composing an X-ray tube device. Further, the container 10 is formed of the containers 11 on both ends, whose inner surfaces are covered with lead plates 12 for shielding X-rays, and the target opposite part 13 which is strongly subjected to thermal radiation from the X-ray tube 20. Thereby, the target opposite part 13 is formed of a material having high thermal conductivity such as Cu and Al, while providing outside an X-ray shielding body 14 so as to enlarge a heat emitting area. Accordingly, when radiating X-rays, the heat generated in the anode 22 can be efficiently emitted outside the container 10 thus reducing the size of a cooling device to be used.