The abatement mechanism of carbon tetrafluoride (CF4) in atmospheric-pressured argon using O-2 as an additive gas under electron beam irradiation and the effect of the pulse duration of electron beams on the abatement were studied by using a kinetic model. About 99% of 1000 ppm CF4 is abated for pulse duration from 0.1 to 10 mu s and an input energy density of 0.85 J/cm(3). The abatement of CF4 decreases to about 70% when the pulse duration becomes longer than 10 ms. This is because the decomposition of CF4 and other products by reaction with activated species and the composition of products by chemical reactions coexist. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3224880]