The synthesis of Mg3N2, a new safe ammonia carrier, by the nitridation of MgO using a simple plasma process is proposed and demonstrated. Recently, ammonia has been considered a promising energy storage material because of its high hydrogen storage density. However, the toxicity of ammonia is an essential safety concern in the storage and transport sector. Hence, a safety ammonia carrier is required for the dissemination of ammonia as an energy carrier. Therefore, in this study, we focus on Mg3N2 synthesis by the nitridation of MgO using an atmospheric pressure nonthermal plasma in a mixed gas atmosphere of N-2 and H-2. At present, 0.3% of MgO nitridation was achieved within 40min of plasma synthesis. If complete nitridation of MgO becomes possible in the future, a breakthrough will occur in the field of energy storage materials.