The wavelet expansion is used to evaluate the spectral dependence in the solution of the radiative transfer equation (RTE). The radiative intensity is expanded in terms of Daubechies wrapped wavelet functions in the wavelength domain. The discrete ordinates method (DOM) is applied to solve the resulting equations. As an example, the nongray radiation through an absorbing, emitting and nonscattering medium between two infinite parallel plates is analyzed. The plates are assumed to be black at constant temperatures. The RTE is solved in an absorption band. The results for the case of radiative equilibrium are given and compared with those obtained by other methods. The accuracy of the method is thus validated.