The present invention provides a method for forming an oxide film on a silicon wafer, comprising: measuring surface roughness of the silicon wafer and/or crystallinity in a surface layer portion of the silicon wafer in advance; adjusting oxidizing conditions for the silicon wafer based on the measurement value; and forming the oxide film on the silicon wafer under the adjusted oxidizing conditions. As a result, there can be provided the method for forming an oxide film by which the oxidizing conditions can be adjusted based on a state of the surface and/or the surface layer of the silicon wafer before forming the oxide film and even an ultrathin oxide film can be thereby accurately formed.