A ceramic scintillator array of an embodiment includes: a plurality of scintillator segments each composed of a sintered compact of a rare earth oxysulfide phosphor; a first reflective layer interposed between the scintillator segments adjacent to each other; and a second reflective layer arranged on a side of surfaces, on which an X-ray is incident, of the plurality of scintillator segments. A difference in dimension between an end portion of a surface of the second reflective layer and a most convex portion of the surface of the second reflective layer is 30 μm or less.