A method for determining a termination time of the step of dispersing a coating composition for a photosensitive layer, containing a binder resin, a powdery charge generating material and a solvent, is disclosed, which comprises (i) providing coating (I) on a substrate by coating the coating composition, following by drying, (ii) providing coating (II) on a substrate by dispersing the coating composition using a dispersion medium to fine the powdery charge generating material, followed by drying, (iii) measuring absorbances of coating (I) at two wavelengths within a short wavelength region and a long wavelength region, respectively, of the spectral absorption wavelength of the charge generating material, (iv) measuring absorbances of coating (II) at the two wavelengthes within the short wavelength region and the long wavelength region, respectively, and (v) calculating spectral absorbance ratios of coatings (I) and (II), respectively, from the following equation: ##EQU1## wherein the dispersing of the coating composition is terminated when the ratio of the spectral absorbance ratio of coating (II) to that of coating (I) exceed a predetermined value.