As a novel technology in ultra-smooth surface machining, atmospheric pressure inductively coupled with plasma jet processing can produce plasma with high density and energy. This capability makes it a perfect medium in fully exciting the reactive gases to improve the material removal rate. This paper is directed towards using the emission spectrometer to monitor and measure the spectra of the plasma jet from 400~1 000 nm. Spectral lines with obvious peaks and large energy differences are selected from the measurement results to calculate the electron temperatures. The measured spectral data are the integrals of emission coefficients along the optical path, and the plasma has a circularly symmetry with respect to the torch axis. Abel inversion transform is employed to compute the emission coefficients of the measured spectrum. These coefficients are then applied to obtain the electron temperatures with Boltzmann plot method. The calculation results denote that the temperature profiles appear to be typically double-peak profiles as a result of the skin effect and swirling inlet flow. With the increasing of off distance, the double-peak effect decreases and the profiles become smooth. The results also indicate that the plasma fringe is somewhat deviate from the local thermodynamic equilibrium, and the applicability of Boltzmann plot method is reduced. Consequently the goodness-of-fit factors, R-Squared values, on the plasma fringe are reduced. The spectra and characteristics of the argon plasma with reactive gas CF4 are also analyzed. This mixed plasma shows bright blue-green color. The reason for the color is that some band spectra emerge between the range of 400~650 nm. These band spectra are the swan bands of diatomic C2 which is formed by the fully excitation of carbon source CF4.