A ceramic scintillator array comprising: a plurality of scintillator segments each composed of a sintered compact of a rare earth oxysulfide phosphor having a composition expressed by a general formula: RE 2 O 2 S:Pr wherein RE is at least one selected from the group consisting of Y, Gd, La, and Lu, and a content of Pr relative to RE 2 O 2 S is 0.001 mol% or more and 10 mol% or less; and a reflective layer interposed between the scintillator segments adjacent to each other in a manner to integrate the plurality of scintillator segments, the reflective layer containing a transparent resin and reflective particles dispersed in the transparent resin, wherein: a content of a phosphate radical, PO4, contained in the sintered compact is set to 150 ppm or less; the reflective particles contain titanium oxide and at least one inorganic substance selected from the group consisting of alumina, zirconia, and silica; the transparent resin comprises an epoxy resin having a molecular structure which has a cyclo structure including no double structure, and an aliphatic skeleton; a glass transition point of the transparent resin is 50°C or higher, and a thermal expansion coefficient of the transparent resin at a temperature higher than the glass transition point is 3.5 × 10 -5 /°C or less; and a change amount in any of pitch of the scintillator segments, warpage of the ceramic scintillator array, and outside dimension of the ceramic scintillator array after the ceramic scintillator array is stored in a packed state for one month in an atmosphere at a temperature of 50°C and a humidity of 80 %RH is 0.02 mm or less. a plurality of scintillator segments each composed of a sintered compact of a rare earth oxysulfide phosphor having a composition expressed by a general formula: RE 2 O 2 S:Pr wherein RE is at least one selected from the group consisting of Y, Gd, La, and Lu, and a content of Pr relative to RE 2 O 2 S is 0.001 mol% or more and 10 mol% or less; and a reflective layer interposed between the scintillator segments adjacent to each other in a manner to integrate the plurality of scintillator segments, the reflective layer containing a transparent resin and reflective particles dispersed in the transparent resin, wherein: a content of a phosphate radical, PO4, contained in the sintered compact is set to 150 ppm or less; the reflective particles contain titanium oxide and at least one inorganic substance selected from the group consisting of alumina, zirconia, and silica; the transparent resin comprises an epoxy resin having a molecular structure which has a cyclo structure including no double structure, and an aliphatic skeleton; a glass transition point of the transparent resin is 50°C or higher, and a thermal expansion coefficient of the transparent resin at a temperature higher than the glass transition point is 3.5 × 10 -5 /°C or less; and a change amount in any of pitch of the scintillator segments, warpage of the ceramic scintillator array, and outside dimension of the ceramic scintillator array after the ceramic scintillator array is stored in a packed state for one month in an atmosphere at a temperature of 50°C and a humidity of 80 %RH is 0.02 mm or less. a content of a phosphate radical, PO4, contained in the sintered compact is set to 150 ppm or less; the reflective particles contain titanium oxide and at least one inorganic substance selected from the group consisting of alumina, zirconia, and silica; the transparent resin comprises an epoxy resin having a molecular structure which has a cyclo structure including no double structure, and an aliphatic skeleton; a glass transition point of the transparent resin is 50°C or higher, and a thermal expansion coefficient of the transparent resin at a temperature higher than the glass transition point is 3.5 × 10 -5 /°C or less; and a change amount in any of pitch of the scintillator segments, warpage of the ceramic scintillator array, and outside dimension of the ceramic scintillator array after the ceramic scintillator array is stored in a packed state for one month in an atmosphere at a temperature of 50°C and a humidity of 80 %RH is 0.02 mm or less.