The possibility of a wide range of adjustment of the hydrophilic-hydrophobic properties of silicon wafers is demonstrated by means of treatment with hydrofluoric acid, Caro's acid, and various concentrations of hydrogen peroxide solutions. By measuring the contact angles of wetting and calculating the total, polar, and dispersive components of the surface energy, it has been found that the most significant hydrophilization of the silicon surface as well as the maximum increase in the surface energy are achieved when the surfice is treated with Caro’s acid, while consecutive processing with Caro’s acid and hydrofluoric acid leads to the most prominent hydrophobization and a decrease in the surface energy.