The book "Quantum Field Theory" by the outstanding American scientist Nobel Prize winner S. Weinberg is a modern course in quantum field theory, covering both the main provisions of this field of theoretical physics and numerous new ideas and modern methods developed in recent years. The second volume gives a modern presentation of the methods of quantum field theory, shows how the application of these methods led to an understanding of weak, strong and electromagnetic interactions of elementary particles. Modern mathematical methods are presented in combination with their applications in elementary particle theory and condensed matter theory. At the same time, much attention is paid to such issues as generalized BRST symmetry, the method of the background field, the method of the effective field applied to the theory of spontaneous symmetry breaking, the method of operator decomposition, superconductivity, the theory of critical phenomena, etc. The presentation is accompanied by numerous tasks placed at the end of each chapter.