In this study, microscale nickel (Ni, 0.33 wt%) and iron (Fe, 0.26 wt%) catalysts coated on cordierite particles were used in the partial oxidation of methane to form syngas by a microwave-assisted process. Microwave treatment can be applied by coupling with materials having higher dielectric loss values. This is because Ni has more electron holes and a higher activity than Fe, and Ni-based catalysts produce heat much faster than Fe-based catalysts upon microwave treatment (208.8 vs 26 ℃/min). Under the same experimental conditions of a volumetric ratio of CH4/air of 1:1, a microwave output power of 450 W, and the reaction time set to 360 min, higher H2 and CO yields were obtained with the Ni catalyst than with the Fe catalyst (54.7 vs 46.0% for H2 and 19.7 vs 14.4% for CO). The coke content was determined to be 0.4 wt% for the Ni catalyst and 0.51 wt% for the Fe catalyst. The shape of the coke was different for the two catalysts; finely shaped coke was observed for the Ni catalyst, whereas thicker multilayered coke appeared on the Fe catalyst.