Recent development in scanning probe microscope techniques has made it possible to investigate, not only microscopic surface topography, hut also physical and chemical properties on the nanometer-scale. We observed the surface potential distribution and molecular ordering in monolayers. The SMM surface potential image clearly shows the existence of micron-sized domains in the polymer monolayers with a good correspondence to the topographical features. This is a first step towards understanding electrical phenomena in organic and inorganic materials with SMM.