Spatially resolved images of an individual C60F18 fluorofullerene molecule on Si(100) - 2 × 1 surface have been obtained using scanning tunneling microscopy. Scanning tunneling microscopy results and ab initio calculations show that the fluorofullerene molecules interact with the Si(100) - 2 × 1 surface with F atoms pointing down towards the surface. The adsorption energy of a C60F18 molecule on Si(100) - 2 × 1 surface is $\sim$12. 1 eV, which is much higher than the adsorption energy of the same molecule on Si(111) - 7 × 7 surface (6. 65 eV). C60F18 molecules are located in the troughs in-between the dimer rows occupying the four-dimer site on Si(100) - 2 × 1 surface. {\textcopyright} 2010 Pleiades Publishing, Ltd.