PROBLEM TO BE SOLVED: To provide an apparatus and method capable of producing organic substances at a low price.SOLUTION: An organic substance production apparatus 1 comprises an organic substance production part 10, a supplying part 12, and a treatment part 15. The organic substance production part 10 has a fermentation vessel 13. The fermentation vessel 13 contains microorganisms which produce an organic substance from synthesis gas. The supplying part 12 supplies a culture medium containing alkali metal sulfide to the fermentation vessel 13. The treatment part 15 obtains alkali metal sulfide by treating with alkali the sulfur content discharged from the organic substance production part 10 to supply the alkali metal sulfide to the fermentation vessel 13.SELECTED DRAWING: Figure 1
