The main aim of this chapter is to give insight into the recovery furnace. In recent times, the recovery furnace is not only used to recover the cooking chemicals in the paper industry but also generate the energy in terms of electricity. In modern days, the demands of the electricity consumptions increase and therefore in order to cater these demand, the new modern recovery furnace need to be developed. In this chapter, we have discussed the early recovery furnace and their development in various functions. The corrosion and erosion is the major issue in any recovery furnace as the concentrated black liquor is the feedstock. Black liquor contains several organic, inorganic and non process elements and hence it is very essential to control the corrosion in the furnace by increasing the heat transfer rate. Several possible solutions have been discussed to enhance the capacity of the furnace by controlling the corrosion and erosion problems incorporated in the recovery furnace. We believe that this chapter gives more insight into the recovery furnace which further helps in the development of this research area.