NOVELTY - Methane fermentation treatment method of foodstuff waste material, involves performing methane fermentation of the foodstuff waste material having lipid ratio in an organic matter of 10% or more, within a methane fermentation tank, crushing and separating the foodstuff waste material, performing solubilization processing in an adjustment tank, and supplying waste liquid discharged from the adjustment tank to methane fermentation tank, where the fermentation is carried out for 40-45 degrees C in methane fermentation tank.    USE - The method is useful for methane fermentation treatment of foodstuff waste material (claimed).    ADVANTAGE - The methane fermentation treatment of foodstuff waste material containing lipid can be carried out efficiently and stably. The method increases the amount of biogas recovery, and does not cause scum formation and foaming. The nitrification and denitrification process can be carried out stably, as the lipid is fully decomposed.    DETAILED DESCRIPTION - Methane fermentation treatment method of foodstuff waste material, involves (a) performing methane fermentation of the foodstuff waste material having lipid ratio in an organic matter of 10% or more, within a methane fermentation tank, crushing and separating the foodstuff waste material, performing solubilization processing in an adjustment tank, and supplying waste liquid discharged from the adjustment tank to methane fermentation tank, where the fermentation is carried out for 40-45 degrees C in methane fermentation tank, or (b) performing methane fermentation treatment of high lipid containing foodstuff waste material having lipid ratio in the organic matter of 10% or more, and other foodstuff waste materials except high lipid containing foodstuff waste material, in methane fermentation tank, crushing and separating high lipid containing foodstuff waste material and other foodstuff waste material in a separate preprocessor, heating and solubilizing the high lipid containing foodstuff waste material in first adjustment tank, and heating and solubilizing the other foodstuff waste material in second adjustment tank, supplying the liquid waste discharged from the adjustment tanks to the methane fermentation tank respectively, where the temperature of first adjustment tank is higher than the second adjustments tank. An INDEPENDENT CLAIM is included for methane fermentation treatment system of the foodstuff waste material.