Stable cluster monolayers are produced on the surface of a Langmuir mo
nolayer of stearic acid, and their surface topography is imaged by sca
nning tunneling microscopy. The clusters are shown to form an ordered
two-dimensional lattice in the monolayer. Electron transport through a
two-barrier tunnel nanostructure is studied. The Coulomb blockage pot
ential of the tunnel nanostructure decreases with increasing cluster n
uclearity.