To effectively utilize a liquid component removed from garbage by subjecting garbage introduced into a hermetically closable container to lactic fermentation and compressing the fermented garbage to remove the liquid compo nent and recovering formed lactic acid while reducing the wt. of the garbage.

Water is added to garbage in a wt. ratio of about 1:1 to grind and mix the garbage and this garbage is introduced into a hermetically closable container to be subjected to lactic fermentation under stirring. When the garbage is compressed after this process, the garbage becomes easy to compress because it is finely divided and a large amt. of a liquid component can be removed. The water content of the garbage is reduced from about 80% to about 50% and the wt. of the garbage itself becomes about 10-20%. In this case, since the liquid component removed from the garbage can be recovered as lactic acid, the liquid component is utilized effectively.