The object of the invention is to realize a light radiation-detecting apparatus including a step of preparing a matrix array including a substrate, an insulating layer arranged on the substrate, a plurality of pixels arranged on the insulating layer, wherein the pixel includes a conversion element converting an incident radiation into an electric signal, and connection electrode arranged at a periphery of the plurality of pixels, fixing a flexible supporting member for covering the plurality of pixels to the matrix array at a side opposite to the substrate, and releasing the substrate from the matrix array.