To provide a multifunctional movable type carbonizing furnace harvesting various valuables from biomass in a short time without requiring special skill in spite of a simple structure.

An apparatus for producing a combustion gas is designed to charge the biomass into a carbonizing chamber 2, control the temperature of the carbonizing chamber with a thermometer 4 provided in the carbonizing chamber, regulate the transport of the combustion gas produced in a combustion chamber 5 with a valve 10 installed in a transport pipe 3 for the combustion gas and thereby regulate moisture and produce charcoal. Carbonized materials, ash, pyroligneous acid and tar are separated with a grate 12 provided in the lower part of the carbonizing chamber and a pyroligneous acid extraction port 7 and a tar extraction port 8 provided in the lower part of a chimney 9.