The band‐gap energyEgof silicon has been reevaluated with high precision between 2 and 300 K by the following method: the derivative of the absorption coefficient, resulting from free‐exciton absorption, has a well‐defined singularity, which can be detected unambiguously by wavelength‐modulation spectroscopy. The energy of this singularity yields the band gap. Our data deviated by more than 5 meV from the earlier results of MacFarlaneet al.and Hayneset al.and fell between theirEg(T) curves. The approximation ofEg(T) =A + BT + CT2givesA= 1.170 eV,B= 1.059×10−5eV/K, andC= −6.05×10−7eV/K2, for 0<T≤190 K, andA= 1.1785 eV,B= −9.025×10−5eV/K, andC= −3.05×10−7eV/K2, for 150≤T≤300 K, which fits our data within 0.2 meV. The major uncertainty of about 1 meV lies in the energies of exciton and TO phonon.