The invention relates to a method for controlling the thermal balance of a suspension smelting and to a suspension smelting furnace. The suspension smelting furnace, comprising a reaction shaft (1), a lower furnace (2), and an uptake (3), wherein the reaction shaft (1) having a shaft structure (4) that is provided with a surrounding wall structure (5) and a roof structure (6) and that limits a reaction chamber (7), and wherein the reaction shaft (1) is provided with a concentrate burner (14) for feeding pulverous solid matter and reaction gas into the reaction chamber (7). The shaft structure (4) of the reaction shaft (1) is provided with cooling means (8) for feeding endothermic material into the reaction chamber (7) of the reaction shaft (1).