The decomposition of CHF3 in a mixture with O-2 and Ar was investigated in a coaxial dielectric barrier discharge at atmospheric pressure. CHF3 decomposition increased linearly in regard to specific energy input (SEI), whereas energy efficiency decreased. The main product was CO2, and its selectivity increased with high SEI and the presence of O-2 in the feed, but an increase of O-2 in the feed led to a decrease in decomposition rate. An increase in total flow rate led to an increase of the absolute amount of CHF3 decomposition and energy efficiency; however, the decomposition of CHF3 decreased. A complete CHF3 decomposition occurred under an SEI of 1.54 kJ/L with the selectivity of CO2 and CO as 89.87% and 7.00%, respectively. Optical emission spectroscopic analysis could explain the available reaction pathways for CHF3 decomposition in the CHF3/O-2/Ar atmospheric plasma and show the possibility of F-2 and HF formation.