Abstract: An industrial kiln employs a tunnel kiln design. An upper portion of a central high-temperature firing region of a kiln body (1) has an arch structure, and is divided into a rising portion (4), a middle portion (5), and a descending portion (6). The rising portion (4), the middle portion (5), and the descending portion (6) are connected by means of curved surfaces with smooth transitions. A transporting mechanism (2) at a lower portion of the kiln body (1) is parallel to the upper portion. The present invention enables collection of excessive heat in a pre-heating portion and a cooling portion to transfer the same to a high-temperature firing portion, thus reducing a firing time and burning fuels of a high-temperature firing region, lowering a production cost, and protecting the environment by preventing exhaustion of a large amount of hot air.