The FTIR (Fourier Transform Infrared Spectroscopy) has been established as a powerful tool for measurements of atmospheric trace gases. Using the sun or moon as light source, between 20-30 trace gases of the tropo- and stratosphere can be detected by their absorption features. The analysis of the spectra allows to retrieve the total zenith columns of the trace gases. For a few trace gases the pressure broadening of the lines allows to get additionally some information on the vertical concentration profiles. Some important trace gases cannot be detected in the IR but in the UV/VIS. This makes it useful to record the whole spectral region from the IR from about 700/cm (14 µm) to the UV at 33000/cm (300 nm).