A fourth-generation dendrimer with 96 thiol functions at its periphery (G4-SH) is used to generate monolayers on various substrates. Whereas gold surfaces tend to organize the approx. 7-8 nm mols. as islands, on mica surfaces G4-SH gives a filament-like pattern that changes to islands in the course of 24 h. Closed monolayers could be gained on silicon by using a special exptl. set up. AFM has been applied to show more or less defect free areas of up to 25 mm2. The height was detd. and found to be reduced by about 70% compared with the size in soln. due to the loss of solvent.