NOVELTY - The fermentation device has heating coils (9,11) whose outlets are connected through pipeline, three-way pipe and valve with the outlet (19) of the heat reserving pot (5) and through pipeline, three-way pipe, valve and transfer pump (12) with the inlets of the solar energy heater (1) as well as the hot-water conversion cylinder (2) and the outlet of the dematerialized water pot (22). The main inlet (13) and outlet pipe (14) of the two heating coils are linked with the pipeline equipped with electro-pneumatic valve (15). Both the main inlet and outlet pipe are fixed with thermometer (16).    USE - Marsh anaerobic fermentation device using solar energy and terrestrial heat for raising temperature.    ADVANTAGE - Uses vacuum tube or heat collecting board, which has a high efficiency of collecting and retaining heat, to gather heat. Includes heat source in reserve so as to offer stable heat for the anaerobic fermentation, heat reserving heat storage pond to make water and heat well-balanced, and thermometer to direct the starting operation of the transfer pumps or the heat source in reserve.    DETAILED DESCRIPTION - The solar energy water heater is made of solar energy vacuum tube or solar energy heat collecting board. The outlets of solar energy water heater and hot-water conversion cylinder (2) are respectively connected to the inlets of two transfer pumps (3,4) through pipeline and valve. The outlets of the two transfer pumps are connected with the inlet (18) of the heat reserving pot through pipeline, valve and three-way pipe, and at the same time with the inlets of the transfer pumps (6,7) respectively through pipeline, valve and three-way pipe. The outlet of one transfer pump (6) is connected through pipeline, valve and three-way pipe to the inlet of the heating coils (9) which are 2 to 30 entwined paralleled coils in the anaerobic pot (8). The outlet of the other transfer pump (7) is connected through pipeline, valve and three-way pipe to the inlet of the heating coils (11) which are 2 to 30 entwined paralleled coils in the regulating pond (10).    DESCRIPTION OF DRAWING(S) - The drawing is a schematic diagram showing the marsh anaerobic fermentation device.    Solar energy heater (1)    Hot-water conversion cylinder (2)    Transfer pumps (3,4)    Heat reserving pot (5)    Transfer pumps (6,7)    Anaerobic pot (8)    Heating coils (9,11)    Regulating pond (10)    Transfer pump (12)    Main inlet (13)    Outlet pipe (14)    Electro-pneumatic valve (15)    Thermometer (16)    Inlet (18)    Outlet (19)    Dematerialized water pot (22)