Oxynitride phosphor powder and its manufacturing method

The oxynitride phosphor having a fluorescence peak wavelength of 587～630Nm, external quantum efficiency is to provide a highly oxynitride phosphor than before. The present invention includes a silicon nitride powder, the substance serving as an aluminum source were mixed with materials to be calcium source, and a substance serving as europium source, in an inert gas atmosphere or in a reducing gas atmosphere, 1500-2000 after obtaining the oxynitride phosphor fired composed mainly of Ca-containing α-sialon as an intermediate product was fired at ° C., under conditions in which there is further Li said acid nitride phosphor fired product not in the active gas atmosphere or in a reducing gas atmosphere, a method of manufacturing oxynitride phosphor powder comprising 50~10000ppm a Li, characterized in that a heat treatment at a temperature below 1450 ° C. ~ the baking temperature.