Abstract: A radiation detector has a photoelectric conversion element array having a light receiving unit and a plurality of bonding pads; a scintillator layer stacked on the photoelectric conversion element array; a resin frame formed on the photoelectric conversion element array so as to pass between the scintillator layer and the bonding pads away from the scintillator layer and the bonding pads and so as to surround the scintillator layer; and a protection film covering the scintillator layer and having an outer edge located on the resin frame; a first distance between an inner edge of the resin frame and an outer edge of the scintillator layer is shorter than a second distance between an outer edge of the resin frame and an outer edge of the photoelectric conversion element array; the outer edge and a groove are processed with a laser beam.