We investigate reactive fluorine atom spectroscopic characterization in atmospheric pressure of He/SF6 plasma using atomic emission spectrometry. As input radio frequency (RF) power levels are raised from 140 to 220 W, the emission spectra of 685.60 (3p4D-3s4P transition) and 739.87 nm (3p4P-3s4P transition) increase significantly. Moreover, an optimal value of SF6 volume concentration in the production of fluorine radicals, which is 0.8% is achieved. Addition of certain amounts of O2 into He/SF6 plasma results in the promotion of SF6 dissociation. Emission intensities of fluorine atoms show the maximum at the O2/SF6 ratio of 0.4.