A method of manufacturing a scintillator, includes growing a scintillator layer constituted by a plurality of column crystals on a base, forming a first protection film so as to cover the scintillator layer, planarizing the first protection film, the planarizing including a polishing process of polishing the first protection film, and forming a second protection film configured to cover the first protection film that has undergone the planarizing. The scintillator layers grown on the base include an abnormally grown portion. In the polishing process, a front end of the abnormally grown portion is polished as well as a surface of the first protection film so as to form a continuation surface by the surface of the first protection film and a surface of the abnormally grown portion.