An organic material production system includes: a pretreatment device (12) that pulverizes a biomass material (11); a hydrothermal decomposition apparatus (14) that hydrothermally decomposes a pulverized biomass (13) by causing it to countercurrently contact with hot compressed water (15), elutes lignin components and hemicellulose components into the hot compressed water (15), and separates the lignin components and the hemicellulose components from a biomass solid residue; a first enzymatic hydrolysis device (19-1) that treats cellulose in a biomass solid residue (17), discharged from the hydrothermal decomposition apparatus, with an enzyme (18) to enzymatically hydrolyze it to a sugar solution containing hexose; a fermenter (21) that produces ethanol by fermentation using a sugar solution (20) obtained by the first enzymatic hydrolysis device (19-1); and a refiner 25 that refines an alcohol fermentation liquid (22), so as to separate it into ethanol (23) and a residue (24).