The development, fabrication, and study of single-atom structures are a continuation of work on creating classical and molecular single-electron devices, carried out in the "Cryoelectronics" laboratory of the Physics Faculty of M.V. Lomonosov Moscow State University since the end of the 80s. During this time, at the Faculty of Physics of Moscow State University, unique nanoelectronic devices have been developed and experimentally demonstrated: a single-electron memory cell with a single electron storage time of more than 8 hours, a single-electron transistor with a record charge sensitivity, the world's first molecular single-electron transistor operating at room temperature, and finally – a single-atom single-electron transistor with a base element approaching the physical limit.