The invention relates to an X-ray image detector, comprising a plurality of X-ray-sensitive sensors and having the following features:each sensor comprises a collecting electrode and a switching element which connects the collecting electrode to an output lead;a photoconductor layer is provided between the individual collecting electrodes and a bias electrode;the collecting electrodes form, in conjuction with reference electrodes, capacitances which can be charged by charge carriers generated in the photoconductor. The invention improves the effectiveness of such an X-ray image detector in that either the surface area of the collecting electrodes is increased or the electric field is distorted by a semiconductor layer so that the majority of the charge carriers generated in the photoconductor flow to the collecting electrodes.