A radiation imaging apparatus comprises a pixel region, on an insulating substrate 100, including a plurality of pixels arranged in a matrix, each pixel having a conversion element 101 that converts radiation into electric charges and a switching element 102 connected to the conversion element 101. The conversion element 101 has an upper electrode layer 119, a lower electrode layer 115, a semiconductor layer 117 arranged between the upper electrode layer 119 and the lower electrode layer 115. The upper electrode layer 119 or the lower electrode layer 115 has an opening 200 at least within a region where the semiconductor layer 117 is arranged.