The coverage and order of dodecanethiolate molecules on InP(110) surfaces is controlled via scanning tunneling microscopy (STM) investigations in dependence of the dodecanethiol dose. Starting from the clean, cleaved semiconductor surface, the STM pictures show the different states of order in the self-assembling films with molecular/atomic resolution. Additionally, scanning tunneling spectroscopy has been applied to distinguish with lateral high resolution between covered and uncovered regions on the surface. Further proof is given by (S)XPS and XPD spectra, obtained from measurements at the synchrotron storage ring BESSY and high-resolution laboratory sources, at all consecutive stages of adsorption.