To solve such problems wherein no conventional carbonization furnace has treated an organic industrial waste having a high water content such as a biomass material at an inexpensive cost, with no air pollution and a decreased amount of exhausted CO2.

This carbonization furnace most effectively combines and circulates the heat from an electric heater and the energy by the combustion of organic materials to be carbonized, as a heating source for carbonization. Thereby the followings are realized: the reduction of an operation cost, the homogenization of the product, the cleanup of exhausted gas and the reduction of the amount of CO2.