PROBLEM TO BE SOLVED: To solve a number of problems in a conventional heat supply device and a heat supply system, wherein fossil fuel such as petroleum, coal and natural gas causing global warning has been directly heat-supplied as main fuel, or the heat supply has been performed in place of electricity generated by power generation or the like using atomic fuel, accordingly, in particular, in the greenhouse cultivation of a farmer, the heating of a building, a cold area or the like, large heat supply becomes necessary for snow-melting measurements, however, a means for satisfying these requirements using inexpensive regeneration energy has not been found. SOLUTION: A heat supply device and a heat supply system are provided for obtaining fermentation heat h by stirring a fermentation material m mixed with, as the fermentation material, a plant system organic matter, a fermentation fungus such as an yeast fungus, and/or an enzyme fungus, and/or a lactic acid fungus, and/or sugars at an optimum blending ratio. COPYRIGHT: (C)2013,JPO&INPIT
