The decomposition of N2O has been studied in a microwave-absorbent assisted discharge of N-2 at atmospheric pressure. Although discharge could not be maintained without using microwave absorbents, stable discharge could be maintained by using two rods type of Zr or W absorbents. The maximum conversion of N2O was greater than or equal to97% at a microwave power of 150-200 W and a distance of 10 mm between the rods. The decomposition mechanisms of N2O in the gas phase and on the hot surfaces of absorbents were discussed on the basis of mass spectroscopic data of products and optical spectroscopic analysis of discharge spectra. The best conversion of O atom in N2O into O-2 was obtained by using Zr rods at the longest distance of 10 nun between the rods and the highest high N-2 flow rate of 1000 sccm. (C) 2003 Elsevier Science B.V. All rights reserved.