METHOD AND DEVICE OF REMOVING NITROGEN TRIFLUORIDE

PROBLEM TO BE SOLVED: To safety and effectively remove nitrogen trifluoride (NF3 ) when NF3 /oxygen containing waste gas and reductive gas are mixed to react and remove NF3 by removing at least a part of oxygen in the waste gas before the reaction. SOLUTION: After NF3 containing waste gas 2 effluent from a NF3 effluence equipment 1 of a CVD device or the like is mixed with diluting gaseous nitrogen fed from a diluting nitrogen feed introducing port 3, it is introduced to a NF3 removing device 16. Here, first at least a part of oxygen in the NF3 containing waste gas 2 is removed by an oxygen separator 6 using a molecular sieve as adsorbent. Next, the NF3 containing waste gas is introduced to a reduction reactor 12, and at this time, reductive gas 9 is mixed with the NF3 containing waste gas at an inlet of the reduction reactor 12 through a flow controller 10 and a reductive gas introducing port 11 to decompose and remove NF3 . The gas from which NF3 has been removed is fed to a fluorine compound treating device 14 where fluorine compounds formed in the reduction reactor 12 is removed.