Polystyrene microparticles can be investigated by using a scanning tunneling microscope. The observed images show the hydrogen atoms on the phenyl groups and the extended polymer chains without entanglement. After a sustained tip scanning, some of the polystyrene surfaces develop a highly ordered structure. Furthermore, the polymerization of styrene monomers can be initiated by the tip field, to form nanometer-scale polystyrene films on graphite substrates, in air at room temperature. The yield was verified by time-of-flight secondary ion-mass spectroscopy.