The lecture contains a summary of the principles for a number of macroscopic quantum effects in condensed matter. Particular attention is paid to physical phenomena that are promising from the point of view of their use in modern electronic devices, signal receiving and processing systems. The “story” is consistently promoted: - from the fundamentals of quantum physics of the condensed state of matter, the band theory of solids and the general principles for describing Bose and Fermi systems with interaction; - to the analysis of promising quantum devices (superconducting quantum interferometers, quantum bits). In particular, the features of charge transfer through simple heterostructures are examined: tunnel contacts; contacts of the superconductor with a normal metal; Josephson junctions.