A conversion apparatus of the present invention includes a pixel region in which a plurality of pixels are arranged. The pixels are including the switching elements and the conversion elements. The pixel region includes a switching element region in which the plurality of switching elements are arranged in row and column directions, and a conversion element region in which the plurality of conversion elements are arranged in row and column directions. A plurality of signal wirings are including a second metal layer, and connected to the plurality of switching elements of the column direction. Bias wirings are including a fourth metal layer, and connected to the plurality of conversion elements. An external signal wiring is including the first metal layer outside the pixel region, and connected to the signal wirings. The external signal wiring and the bias wiring intersect each other.