The energy demand has been dramatically increasing due to rise in global population and rapid industrial growth depleting non-renewable resources such as fossil fuels, minerals and nuclear energy. In addition to this, large amount of wastewater is generated from domestic and industrial activities which needs to be treated wisely to meet the demand of future generations. Recently, microbial fuel cell (MFC) emerged as a promising novel technology to generate electricity using wastewater sources, based on inherent property of microbial electron transport chain system. MFCs uses catabolic potential to break down complex organic compounds present in wastewater to release source of electrons that can be further used for electricity generation. The present chapter delves into the fundamental working principle, key features, types and various components used for making an efficient MFC system. In addition, it discusses various types of microbes and factors influencing the performance of MFCs. Besides this, various advantages and disadvantages of using MFCs including the economic and scientific challenges for greater aims and better efficiencies for its possible practical applications and its alternative as a source of renewable energy for its future use.