Production of ready-to-use solutions

A process for the direct preparation of cleaning solutions for semiconductor manufacture which comprises generating the cleaning solutions directly at the site of use by mixing at least one of the gases selected from the group consisting of NH3, HCl and HF with water or aqueous solutions, wherein the gas or gases to be added are metered into an inlet chamber and the resultant crude mixture is passed from the inlet chamber to a mixing chamber, which contains a static mixer, where the mixture is homogenized.