Abstract: Zinc sulfide phosphor that has high energy efficiency and color purity and that emits blue light is provided. Specifically, a zinc sulfide phosphor adapted for use as a light source or in a display by being applied to powder EL elements is provided. The zinc sulfide blue phosphor comprises copper, silver or both elements and nickel, iron or both elements. The phosphor is obtained by adding a compound comprising copper, silver or both elements, a zinc compound, a sulfidizing agent and a compound comprising nickel, iron or both elements as an aqueous solution to an organic solvent to form a reaction mixture, heating the mixture and removing water from the reaction mixture by azeotropic dehydration of water and the organic solvent to obtain a zinc sulfide phosphor precursor, further sintering the zinc sulfide phosphor precursor.