To provide a combustion apparatus of simple structure capable of continuing stably high temperature combustion even when a biomass contains a large amount of moisture, capable of gasifying the moisture by water gasification reaction to bring a plus side effect as the heat generation amount, in the lower gasification combustion type combustion equipment, a carbonization furnace capable of taking out a little by a little a carbide (carbonized product) of high quality by live charcoal combustion in the combustion equipment, and a gasification furnace equipment for generating production gas from the carbide of high quality by providing a reducing chamber.

A narrow opening part 15 is provided in the bottom central part of a primary combustion chamber 13, a gasification combustion chamber grate 17 is mounted to cover the opening part 15, and to provide a space for converging flame F, combustion gas B and ashes G thereon, a ship bottom-shaped conical sloped face furnace floor 14 is formed using the opening part 15 as the center of a bottom to burn fuel three-dimensionally, a sufficient required number of combustion air holes 10 is provided in the sloped face furnace floor 14 and a wall of the primary combustion chamber 13, the flame F, and the combustion gas B and the ashes G are passed through the gasification combustion chamber grate 17 to be guided to a secondary combustion chamber 16 through the opening part 15.