PURPOSE: To improve the shock resistance of an X-ray detector by providing each electrode plate used as a signal plate with dummy projections in addition to a projection for taking out a signal and connecting the signal-taking-out projections to a wiring pattern through a conductive material and connecting the dummy projections to the wiring pattern through an insulating material.

CONSTITUTION: An X-ray detector for a CT scanner or similar device is constituted by alternately stacking several pieces of electrode plates 7a to which high voltage is to be applied and several pieces of electrode plates 7b for taking out signals before the thus formed body is installed in an inactive gas such as xenon. The plates 7a are connected together by inserting their projections 13 into the insertion holes of a conductive plate 11 before soldering is performed. Each plate 7b has three projections 17 one of which is used for taking out a signal and attached to a printing wiring plate 15 and the other two are attached to the plate 15 with an insulating adhesive member 10 interposed. Because of the above constitution, it is possible to install the plates at very small intervals. It is also possible to prevent the generation of noise by preventing any capacity changes which might be caused by vibration.