An intraoral sensor includes an image sensor, an FOP, a scintillator, a case, and a signal cable. The FOP includes a first main surface, a second main surface, and a plurality of lateral surfaces. The first main surface and the second main surface have a polygonal shape. An edge of the second main surface is constituted by a plurality of corner portions, and a plurality of side portions connect the corner portions adjacent to each other. The scintillator is provided on the second main surface and the plurality of lateral surfaces in such a manner that a second corner portion out of the plurality of corner portions and a second ridge portion are exposed. The second corner portion located on a second direction side opposite to a first direction in which the signal cable extending beyond, and the second ridge portion constituted by the lateral surfaces adjacent to the second corner portion located on the second direction side and adjacent to each other.