Patent attributes
In the present invention, a gas flow restraining ring facing corner portions of the front face of a substrate horizontally held on a substrate holding unit and movable up and down, is set to a predetermined height in accordance with a coating treatment. Then, a coating solution containing a coating film forming component and a solvent is applied to the front face of the substrate and spread into a thin film state by a so-called spin coating method, and thereafter the substrate is rotated at a high speed so that the coating solution is dried. In this case, it is possible to control fresh gas flow from above the substrate to decrease the difference in evaporation rate of the solvent between the coating solution on the corner portions of the substrate and the coating solution inside them, thus enabling the coating treatment uniform within a plane on the substrate.