There is disclosed an X-ray computer tomography system having an X-ray tube (1) for producing X-rays, an X-ray detector (2) including plural detector modules (6), a rotation mechanism by which the X-ray tube and the X-ray detector are held so as to be rotatable about an axis of rotation, a reconstruction unit (4) for reconstructing images based on the output from the detector, and a display unit (5) for displaying the reconstructed images. Each of the detector modules (6) has plural detector elements (7) arranged in a matrix. The detector elements act to detect the X-rays transmitted through a subject to be examined. The detector modules (6) are arranged along a reference axis substantially perpendicular to the axis of rotation and tilted relative to the axis of rotation.
