The VUV-photodegradation of polytetrafluoroethylene (PTFE) ultra-thin film was studied by ultraviolet photoelectron spectroscopy and quadrupole mass spectrometry. These results were compared with the previous photodegradation studies of the polyvinylidenefluoride (PVDF) and polyethylene (PE). Generation of new peak, π-band originated from the CC bond, was observed in the low binding energy region of the UPS spectra in both PVDF and PE during the photodegradation. In contrast, no new peak generation was observed in the UPS of the photodegraded PTFE. Mass spectrometry analysis also suggested that the CC bond generation is not a major mechanism in the VUV photodegradation of PTFE.