In a multi-source X-ray CT scanner having multiple X-ray sources, an imaging FOV size is fixed. In the X-ray CT scanner, a position of at least one of multiple X-ray generators is movable in the Z-axis direction (in the rotation axis direction). It is further possible to configure such that while shifting the X-ray generator, the rotation speed of the rotating plate is kept to be a predetermined value or less. Highly precise CT measurement is implemented as to various imaging FOV sizes, without exposing the test subject to ineffective radiation.
