A coating process and apparatus; the apparatus including a unit for forming a mixture that includes at least one precursor of a surface reaction, a unit for atomizing the mixture into droplets, a unit for transporting the droplets of mixture towards a surface of a substrate to be coated with the surface reaction. The unit for forming a mixture are adjusted to mix to the mixture a liquid carrier substance, which is not a precursor of the surface reaction, and the boiling point of which in the defined process space is lower than the boiling point of the precursor of the surface reaction. The proposed arrangement improves both speed and quality of the coating process.