  In the framework of the Standard Model (SM) a theoretical description of the
neutron beta decay is given at the level of 10^{-5}. The neutron lifetime and
correlation coefficients of the neutron beta decay for a polarized neutron, a
polarized electron and an unpolarized proton are calculated at the account for
i) the radiative corrections of order O(\alpha E_e/m_N) ~ 10^{-5} to Sirlin's
outer and inner radiative corrections of order $O(\alpha/\pi)$, ii) the
corrections of order O(E^2_e/m^2_N) ~ 10^{-5}, caused by weak magnetism and
proton recoil, and iii) Wilkinson's corrections of order 10^{-5} (Wilkinson,
Nucl. Phys. A377, 474 (1982)). These corrections define the SM background of
the theoretical description of the neutron beta decay at the level of 10^{-5},
which is required by experimental searches of interactions beyond the SM with
experimental uncertainties of a few parts of 10^{-5}.
