We report a new experimental method allowing the direct observation of Langmuir films at the air/water interface by atomic force microscopy. Using this method a quantitative observation of multilayer formation in various systems, such as gold nanoparticles and polymerized octadecyltrichlorosilane layers, could be achieved. In particular, a high vertical resolution is reached (around 1 nm) which enables topographic measurements on Langmuir multilayers in the submicrometer range.