Scanning Tunneling Microscopy (STM) has become one of the basic techniques for the analysis of surface reconstructions, overlayer growth mechanisms, surface dynamics and chemistry at the atomic scale. STM is used in physics, chemistry and biology for investigation of organic and inorganic nanoobjects. However, the mechanisms of STM image formation are still not completely understood. The proposed project will be focused mainly on two unresolved issues. The first research focus is related to fabrication of functionalized STM probes with well defined electronic (orbital) structure. To control the electronic structure of the STM tip apex, oriented single crystal probes will be used. The second research focus is related to experimental and theoretical studies of the STM tip and surface atoms interaction and the role of different electron orbitals of the both tip and surface atoms in the STM image formation process. The atom-atom interaction at extremely small tunneling gaps as well as distance and bias voltage dependent contribution of separate electron orbitals will be studied experimentally using scanning tunneling microscopy and spectroscopy at room and low temperatures. The experimental data will be analyzed in a conjunction with results of theoretical (density functional theory and tight binding) calculations. The project activity can provide new fundamental understanding of the atomic scale objects and give some keys for controllable probing separate electron orbitals of individual atoms with STM. This can advance the surface analysis methods necessary for development of nanoscience and nanotechnology. The selective orbital imaging capability can allow to reach ultimate spatial resolution, spin sensitivity at the atomic scale and controllable chemical discrimination of atomic species on surfaces using STM that are essential for physics, chemistry, biology, medicine and materials science.