PURPOSE: To form a coating layer of a uniform mixture of plural materials on a substrate.

CONSTITUTION: At least two liquid flows are injected toward a bell mouth 324 of a rotary type sprayer 320 and are coupled substantially in the bell mouth 324 of the rotary type sprayer 320, by which the bell mouth 324 is forced to atomize and mix the fluid flows and to form the substantially homogeneously atomized mixture. The mixture is then adhered onto the substrate 18 in the form of the layer on the substrate 18. This method is useful for adhering the plural different materials, such as two charge generating pigments, onto the surface of the substrate 18 of the photoreceptor, etc. These materials are bonded in the bell mouth 324 of the rotary type sprayer 320 and are then dried or polymerized and, therefore, the intimate mixing of the different materials which are usually non-bondable to each other on account of the interaction, such as flocculation, between the plural materials and the formation of the single layer thereof on the substrate 18 are made possible.