Abstract: A method for analyzing impurities within a silicon wafer in a convenient and simple manner with high accuracy and sensitivity. In a first example 1, a silicon wafer is subjected on its surface to a sandblasting process with use of powder of SiO2 and then to a thermal oxidation process in a dry-oxygen gas atmosphere to easily move impurities present within the silicon wafer into a distorted layer and to form a thermal oxide film and a surface layer of the wafer positioned directly therebelow and containing the distorted layer. The thermal oxide film or the surface layer containing the distorted layer is dissolved with, e.g., a solution of hydrofluoric acid to recover and analyze the dissolved solution. In a comparative example 1, the same processes as in the example 1 are carried out to analyze a predetermined solution, except that the sandblasting process is omitted.