A spectrometer with outer high-Q optical cavity and non-coherent radiation source in the range 0.9 µm and spectral resolution of 0.08 cm-1 is designed. A halogen lamp of 100 W was used as the radiation source. Absorption spectra of atmospheric air and ethanol near 0.9 µm were recorded with the spectrometer. The signal contrast coefficient of the spectrometer turned out to be 65 comparative to standard spectrophotometric method all other parameters equal.