To adjust the position of the focus of an X-ray tube with a high degree of freedom and a high resolution.

The electron beam of the X-ray tube is deflected in two-dimensional directions and the focus of the X-ray tube is made movable in an optional direction. For instance, two electrodes 114a and 114b in a rod shape parallel to an x direction are provided so as to hold the electron beam (e) in a z direction emitted from an electron gun 113 to a rotating anode 112 therebetween in a y direction. Also, two electrodes 114c and 114d in the rod shape parallel to the y direction are provided so as to hold the electron beam (e) therebetween in the x direction. A voltage is applied between the electrodes 114a and 114b to form an electric field E1 in the y direction, and a voltage is applied between the electrodes 114c and 114d to form an electric field E2 in the x direction. The electron beam e is deflected in the y direction by the electric field E1 and is deflected in the x direction by the electric field E2.

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