  The present lectures are a practical guide to the calculation of radiative
corrections to the Green functions in quantum field theory. The appearance of
ultraviolet divergences is explained, their classification is given, the
renormalization procedure which allows one to get the finite results is
described, and the basis of the renormalization group in QFT is presented.
Numerous examples of calculations in scalar and gauge theories are given.
Quantum anomalies are discussed. In conclusion the procedure which allows one
to get rid of infrared divergences in S-matrix elements is described. The
lectures are based on the standard quantum field theory textbooks, the list of
which is given at the end of the text.
  These lectures were given to the 4-th year students of the Department of
General and Applied Physics of the Moscow Institute of Physics and Technology
(Technical University).
