Abstract: A closely packed film comprising at least one unimolecular layer which contains at least one amphiphilic compound whose hydrophobic molecular region comprises at least one hydrocarbon chain which has been chemically modified, at least terminally, is distinguished by very good adhesion between the film and the adjacent layer (monolayer or substrate) on contact between the hydrophobic region of the film with the hydrophobic surface of the adjacent layer, and on contact between the hydrophilic region of the film and the hydrophobic region of the adjacent layer, and vice versa.Films of this type can be used with advantage, for example, for improving the surface-slip characteristics of the substrate, in the production of sensors or in semiconductor technology.