PURPOSE: To suppress the drop of brightness by improving an adhesive applied between phosphor in the light emitting layer of a dispersed EL element and an organic binder.

CONSTITUTION: A phosphor 3 shown in figure 2 obtained by applying uniform dispersion process of fine particles of polymers going to be subjected to film formation to the surface of a phosphor by a ball mill device, and next, the film formation process is carried out by a low fusing point organic solvent for dissolving the polymers partially. Accordingly, adhesion is improved by the polymer on the surface of the phosphor and an organic binder jointing with each other, and the secular deterioration of brightness is suppressed.