To provide an optical detector configuration body suitable for detecting a single photon event.

An optical detector configuration body comprises a detection region 1 where such electric charge as representing an incident radiation which the region detects is generated. The detection region is substantially square, and provided with plural transfer electrodes arrayed, diagonally, across the detection region. With a clock pulse provided to a terminal 5, an electric charge is transferred to a single output 3 across the detection region 1, then sent to a voltage-sensitive diode 4. The optical detector configuration body may be so designed as to have a large detection region with smaller capacitance, which is especially appropriate for detecting a single X-ray photon. In order to improve an electric charge transfer efficiency to a device, an auxiliary channel, or a notch, is contained in a base body of the detection region.