The purpose of this work is to collect and interrelate the fundamental concepts about exergy transfer analysis and local exergy cost applied to the analysis of microwave heating systems. First, thermoeconomics and exergoeconomics are reviewed. Local exergy analysis is presented next, including local efficiency, and local cost associated. Emphasis is put on local cost that an electromagnetic field can generate and its association with microwave heating exergy. Unsteady-state of exergy cost transfer and exergy costing are difficult to perform during microwave heating due to the complex combination of electromagnetic fields and heat transfer analysis, while the electromagnetic field distribution occurs at a time scale of nanoseconds, heat and exergy cost transfer occurs at time scale of seconds. For this reason, simulations reported to date deal only with cases of First and Second Law of Thermodynamics with no mention of local efficiency or local cost, leaving an open promising field of research. By and large, results are presented for two heating methods, conventional and microwave. (C) 2014 Elsevier Ltd. All rights reserved.