Provided is a treatment system whereby a wet organic waste can be effectively treated and CO 2 produced in the course of the treatment can be immobilized to thereby contribute to the reduction of CO 2 . The treatment system is characterized by including microbiologically fermenting a wet organic waste in a fermentation device, combusting in a combustion furnace a fermented material obtained from the fermentation device and, at the same time, supplying to the combustion furnace a fermentation gas produced by the microbiological fermentation treatment in the fermentation device, and then recovering and immobilizing CO 2 in a hot exhaust gas produced by the combustion treatment in the combustion furnace.
