A heat-pipe high-temperature cell of the White cell type was constructed for sensitive detection of the spectra of high-temperature molecules. It has been incorporated into the optical system of a tunable diode laser spectrometer. With a 40 m optical path length abundant spectral lines of the DELTAupsilon=2 vibration-rotation bands of NaBr have been observed in the wavenumber range between 560 and 600 cm-1. The technique of spectrum processing by use of Fourier transformation was applied to the source-modulated diode laser spectrum to eliminate fringes and to improve the signal-to-noise ratio.