In this talk I will review the status of the Standard Model theory of neutron beta decay. Particular emphasis is put on the recent developments of the inner''™ andouter'' electroweak radiative corrections, and the isospin-symmetry-breaking correction to the Fermi matrix element. The use of dispersion relation, lattice Quantum Chromodynamics and effective field theory framework allows for high-precision theory calculations at the level of \(10^{-4}\), turning neutron beta decay into a powerful tool to search for new physics. I offer an outlook to the future improvements.