Abstract: A phosphor expressed fundamentally as YA10.sub.3 :Ce is produced through baking under a usual condition of a mixture of Y.sub.2 O.sub.3, Al.sub.2 O.sub.3, CeO.sub.2 and a controlled amount of barium compound exemplified by BaCO.sub.3, BaO, Ba(OH).sub.2 and BaF.sub.2. The presence of the barium compound in the mixture causes intensification of ultraviolet emission and/or suppression of the formation of blue-emitting Y.sub.3 Al.sub.5 O.sub.12 :Ce. The use of BaF.sub.2 as the barium compound or partial replacement of at least one of Y.sub.2 O.sub.3 and Al.sub.2 O.sub.3 respectively by YF.sub.3 and AlF.sub.3 is favorable to the intensification of the ultraviolet emission.

Abstract: A cerium-activated yttriumaluminate phosphor such as YA10.sub.3 :Ce featuring an enhanced luminous intensity is produced by adding a barium compound exemplified by BaO, BaCO.sub.3, Ba(OH).sub.2 and BaF.sub.3 to a mixture of source materials of the host material and the activator and baking the resulting mixture at a usual temperature ranging from 1000.degree. to 1400.degree. C. The barium compound preferably amounts to 0.001-8 mol% of the yttriumaluminate and may alternatively be introduced into a preliminarily baked and pulverized mixture of the source materials.