A method is studied for simultaneously determining the vertical profiles of a series of atmospheric minor gases (H₂O, O₃, N₂O, CH₄, CFC-11, CFC-12, and CO) on the basis of ground-based measurements of downward thermal radiation in the range from 3 to 17 μm with a spectral resolution of 0.4 cm^-1. It is shown that the measurements performed under clear-sky conditions make it possible to determine the total contents of minor gases with errors from 1-2% (for H₂O) to 11.5% (for CO). Spectral measurements of downward radiation can also be used to determine gas contents within several atmospheric layers. The corresponding errors in gas content determination are as follows: 1.5-2.5 and 8.5-14.5% for water content in the lower and middle troposphere, respectively; 5-7 and 3-5% for ozone in the troposphere and stratosphere, respectively; and 4-9% for methane in the boundary layer and free atmosphere. For the atmosphere of a low water content, a spectralangular measurement scheme makes it possible to reduce the errors in the total content of chlorofluorocarbons to 3.7 and 4.4% for CFC-11 and CFC-12, respectively.