The thermal pyrolysis of chlorodifluoromethane (R22) for producting tetrafluoroethylene (TFE) has been studied using the tutular reactor designed by the authors. The reaction temperature over 600∼850℃, residence time over 0.005∼0.6 sec, and steam/R22 ratio 3 to 30 were varied through experiments to analyze the effect of these variables on the conversion of R22 and selectivity for TFE. We have provided the guidelines for the optimal operation and design for the pyrolosis reactor. With increasing the dilution ratio, not only the conversion of R22 but also the selectivity for TFE increase. The optimum range of reaction temperature was 700∼750℃ and the residence time 0.07∼0.1 sec. In the kinetic study, first order rate equation was fitted well with the experimental data. This indicates that the main reaction step is a CF₂ generation from R22 pyrolysis. The range of activation energy for the rate constant was obtained 44.7∼48 kcal/mol.