The present invention relates to imaging devices. Technical solutions—creation of highly manufacturable assemblage of flat panel x-ray detectors, and providing high quality images. The flat panel x-ray detector comprises a light-blocking split housing consisting of a bottom and top parts; in the housing sequentially along the incident radiation pathway are installed an elastic radiotransparent layer, x-ray screen on the substrate and sensors being fastened to the mounting base. Sensors are fastened on the mounting base with a possibility to be removed with a possibility to be removed by means of additionally set on the sensor substrates intermediate elements. To fix the screen it is additionally introduced a bar inside which the edge of said screen substrate is fixed, and the bar is fastened to mounting base with a possibility to be removed.