A mixed melt, which contains urea and/or a urea derivative and contains a
metal compound, is prepared. The mixed melt is solidified, by heating,
whereby the urea and/or urea derivative is decomposed, a precursor being
thereby prepared. The thus prepared precursor is ground, and then the
thus ground precursor is fired. The metal of the metal compound may be at
least one kind of a metal selected from the group consisting of Al, B,
Ba, Be, Bi, Ca, Cd, Cs, Ga, Ge, Hf, In, K, Li, Mg, Mo, Na, Nb, P, Rb, Si,
Sn, Sr, Ta, Ti, V, W, Zr, and rare earth metals. A finely powdered
phosphor free from inclusion of impurities and having uniform particle
size is thus produced at a low cost and efficiently.