We have investigated the possibility afforded by epitaxial ferroelectric oxide thin films to control and image locally the polarization field of ferroelectrics over large areas with submicron resolution, using the metallic tip of an atomic force microscope as a mobile top electrode and local probe of the ferroelectric properties. Atomically smooth films ofPb(Zr0.2Ti0.8)O3,showing a root-mean-square roughness of typically a few angstroms, could be uniformly polarized and imaged over areas as large as2500 &mgr;m2without introducing any topographic disorder. Regular arrays of 100 nm wide lines and circular domains with a diameter less than 100 nm were written in arbitrary areas of the uniformly polarized regions. ©1998 American Institute of Physics.