A thin liquid coating film is coated on a surface of a solid substrate, e.g. a glass plate, by using an incomplete liquid container having an opening of a shape similar to the shape of the surface of the substrate on one side thereof. First the substrate and the incomplete container are brought into tight contact with each other such that the side opening of the container is closed by the surface of the substrate, whereby the container is completed. Next, a coating liquid is fed into the container to thereby wet the substrate surface, and then liquid is extracted from the container so as to lower the liquid level in the container at a predetermined rate while keeping both the container and the substrate stationary. By this method a submicron coating film of uniform thickness can easily be formed even on large-sized substrate, and it is easy to form a coating film on only a limited area of the substrate surface without using any masking.