Infrared absorption spectra and absorption cross-sections in the C--H deformation band of CH3OOH near 1320 cm-1 have been measured with a tunable diode laser spectrometer. Methylhydroperoxide concentrations in a slowly flowing gas mixture were determined by UV absorption. Peak absorption cross-sections of the strongest lines observed were found to lie in the range (0.5-1.5)¿10-18 cm2 under near Doppler-limited conditions. The dependence of the peak absorption cross-sections on total air pressure in the range 2.5--90 torr was also investigated, and the possibility of CH3OOH atmospheric mixing ratio measurement with a tunable diode laser assesed. ¿ American Geophysical Union 1989