One of the major problems of archaeometallurgy is the identification of furnaces, which is very often based on the presence of burnt soil and slag, which can appear there accidentally. However, it is necessary to follow several principles: reconstructing the functioning of the object and correspondence between this reconstruction and smelting processes reconstructed from analyses, the presence of metallurgical residuals, and analogies in other cultures. This approach was applied to 128 objects from the Bronze Age settlement of Arkaim, divided into 8 types. As a result, it has been found that some types (long furnaces, furnaces near walls) had been used for heating (use for other domestic needs is not excluded); fireplaces and furnaces with/without chimneys had been used for heating, and other domestic needs; fireplaces filled with small stones served for some operations that required high temperatures for a long time; and the functions of pit furnaces have remained unclear. The only type reliably connected to ore smelting is the furnace attached to the well, with/without a horizontal chimney. Later, this type became typical of the Alakul culture and the Final Bronze Age developments.