**Abstract**

Indoor air pollution due to inefficient use of solid biomass fuels in traditional cookstoves causing serious threat to human health and millions of deaths, mainly in developing countries. This chapter reports parameters for measurement of thermal as well as emission performance of biomass cookstoves. The thermal performance parameters include fire power, efficiency, specific fuel consumption and turn-down ratio whereas the emission performance parameters include emission factor or indoor concentration of a pollutant. This chapter also reports about technological improvements in the biomass cookstoves. Since early 1980s, efforts were made by the researchers for development improved cookstoves. These efforts include use of metals as cookstove materials, provision of grate for better air circulation, air preheating, provision of swirl and secondary air, provision of insulation, use of chimney, baffles etc. The improved cookstoves were found to be causing saving in biomass fuel but there was not much improvement in emission performance of these stoves as compared with their traditional versions. The research on advanced biomass cookstoves started in early twenty-first century. While designing these cookstoves, advancements in technologies such as insulating the combustion chamber, supplying correct amount of primary and secondary air at right place into the combustion chamber, use of fan to create draft, use of gasification techniques, use of high density pellets as fuel etc. are being used. Advanced biomass cookstoves are found to be highly fuel efficient and they cause negligible pollutant emissions. Various factors affecting adoption of improved biomass cookstoves such as social, functional, and cultural are discussed in detail. Recommendations for use of energy efficient and clean cooking options are also given.

**Keywords:** energy efficiency, emission, indoor air pollution, adoption, cookstove
