To understand the functioning of the scanning tunneling microscope I describe some basics of quantum mechanics. I present the process of particle tunneling. Measurements with scanning tunneling microscope are usually done in ultra high vacuum, otherwise samples get quickly contaminated. My aim is to incorporate experiments with scanning tunneling microscope into educational process, so I have focused on scanning tunneling microscopy in air which is cheaper, but has some restrictions. Air pressure is a factor we cannot ignore when talking about sample and tip contamination. For measurements in air we need samples that stay clean for long enough so I present samples adequate for measurements at ambient conditions. I describe known experiments on such samples. The thesis also contains my own mesurements on oriented graphite (HOPG), gold Au(111) and gold with graphene nanoribbons GNR/Au(111) with tungsten (W) and platinum/iridium (Pt/Ir) tips. I have reached atomic resolution on HOPG and I have also seen steps on Au(111). The GNR/Au(111) sample has probably been contaminated which has prevented acurate measurements.