The present invention relates to a method for preventing or reducing contamination of a surface of a substrate, or protecting a surface of a substrate by making a surface of a substrate hydrophilic, by means of arranging, successively in relation to the substrate, a first layer containing a negatively-charged substance, and a second layer containing a positively-charged substance or containing a positively-charged substance and a negatively-charged substance on the surface of the substrate or in a surface layer of the substrate. In accordance with the present invention, a novel method for preventing or reducing adhesion of contaminants, and color degradation or color change of a substrate over time, can be provided.
