An organic material production system using biomass material includes: a hydrothermal decomposition apparatus that causes the biomass material and hot compressed water to countercurrently contact with each other and undergo hydrothermal decomposition, so as to separate the lignin component and the hemicellulose component from a biomass solid residue; a cellulose enzymatic saccharification device that treats, cellulose in the biomass solid residue, so as to enzymatically saccharify the cellulose to a first sugar solution containing hexose; an alcohol fermenter that produces alcohols by fermentation using the obtained first sugar solution; a sulfuric acid decomposition device that decomposes the hemicellulose component in hot water discharged from the hydrothermal decomposition apparatus, which contains the eluted lignin component and the eluted hemicellulose component, so as to decompose the hemicellulose component to a second sugar solution containing pentose; and a second alcohol fermenter that produces, using the second sugar solution containing pentose, alcohols by fermentation.