A phosphor with high efficiency having an excitation band corresponding to light of the ultraviolet-visible (300 to 550 nm) wavelength region emitted from a light emitting element which emits blue or ultraviolet light is provided. Commercially available CaO [3N], Si.sub.3N.sub.4 [3N], and Eu.sub.2O.sub.3 [3N] are prepared, respective materials are weighed and mixed to have a mol ratio of CaO:Si.sub.3N.sub.4:Eu.sub.2O.sub.3=1.4775:1:0.01125, and then the mixture is heated to 1600.degree. C. by a heating rate of 15.degree. C./min under a nitrogen atmosphere and retained and fired at 1600.degree. C. for three hours. Thereafter, the raw materials are cooled down from 1600.degree. C. to 200.degree. C. for an hour to thereby produce a phosphor having a composition formula Ca.sub.1.58Si.sub.3O.sub.1.63N.sub.4.35:Eu.sub.0.024.