Fluoride crystal

Patent Granted PROBLEM TO BE SOLVED: To provide a fluoride that emits light at high luminance in a vacuum UV region, and to provide a new vacuum UV light emitting element comprising the fluoride, suitable to be used for photolithography, cleaning of substrates of semiconductors or liquid crystals, sterilization, next-generation high-capacity optical discs and medical treatment (ophthalmologic treatment, DNA cutting) and the like, and to provide a vacuum UV light emitting scintillator suitable to be used for a small-size radiation detector in which a diamond light receiving element or an AlGaN light receiving element having low background noises are assembled as a substitute of a conventional photomultiplier tube.