An onsite integrated production factory having an electrolytic plant, an ethanol plant, a vegetable plant, a culturing plant, and a power generation unit. The onsite integrated production facility is arranged so that fresh water, sulfuric acid or caustic soda produced by and received from the electrolytic plant is used in the ethanol plant to produce and output oxalic acid, sodium oxalate, fuel bioethanol. The oxalic acid or sodium oxalate produced in and received from the ethanol plant is used for removing calcium contained in the sea water in the electrolytic plant. The vegetable plant produces vegetables for generation and outputting of oxygen by receiving the carbon dioxide generated during the fermentation process in the ethanol plant and fresh water from the electrolytic plant. The culturing plant has a fishery farm or reef for using the oxygen generated in the vegetable plant.