The infrared and millimeter-wave spectra of isotopically pure chlorodifluoromethane (HCFC-22) have been investigated for the ν 5 = 1 excited state. IR spectra of CHF 2 35 Cl were recorded at room temperature with high resolution (0.0021 cm −1 , Bruker IFS 120 HR) in the region between 560 and 650 cm −1 . The spectral analysis of CHF 2 Cl allowed us to assign 7788 lines (J≤ 70) to the ν 5 a/c-hybrid band (ν 0 = 596.3714 cm −1 ). The millimeter-wave rotational spectrum for the ν 5 = 1 state was also assigned and measured in the frequency range 8–340 GHz andJ≤ 78. The data set contains 208 transitions. The abundance of experimental data enabled us to perform a simultaneous least-squares fit of IR and MW data to determine most of the molecular parameters describing the excited state. Moreover, we were able to determine approximate band centers for several hot bands in the region, which were not studied in detail.