The paper is dedicated to the study of methane steam reforming using three channels rotating discharge model of glidarc reactor. The process is described in terms of methane conversion, process selectivity, and energy cost as a function of discharge frequency. The analysis gives information on the reactor's exploitation parameters in order to optimise its chemical performances. The experimental observations are in good agreement with a proposed model describing the chemical evolution of the system. (C) 2003 International Association. for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.