Auger electron spectra (AES) and Auger electron photo-ion coincidence (AEPICO) spectra of poly(vinlylidene fluoride) (PVDF) were observed to study the mechanism of effective fluorine ion (F+) desorption by irradiation of photons corresponding to the transition from F 1s to s(C-F). In the AES at photon energy (hυ) = 690.3 eV (from F1s to |σ|(C-F)), the spectator-Auger shift is about 3 eV. At hn = 690.3 eV the contribution of spectator Auger electron to the observed Auger spectrum is large. In the F+ AEPICO spectra at hυ = 690.3 eV an intense peak appears. The peak positions of the F+ AEPICO spectra are in agreement with those of the Auger spectra. These results indicate that the mechanism for effective F+ ion desorption induced by the transition from F1s to σ(C-F) occurs through the spectator-Auger processes. The efficiency of ion desorption depends on the electronic structure of the spectator-Auger final state.