NOVELTY - The biofuel producing device comprises a supercritical water gasification reactor equipped with a high temperature electric furnace filled with a metallic catalyst and a biomass including microalgae and water, a cooling device for cooling the product from a supercritical water gasification reactor at 70-80 degrees C, and a separator for separating the cooled product into a liquid phase product and a gas phase product. The supercritical water gasification reactor is operated at a temperature of 450-600 degrees C and a pressure of 200-300 bar using supercritical water.    USE - Biofuel producing device.    ADVANTAGE - The device is capable of economically, simply and rapidly producing the biofuel at low reaction temperature with high yield and excellent storage stability.    DETAILED DESCRIPTION - The biofuel producing device comprises a supercritical water gasification reactor equipped with a high temperature electric furnace filled with a metallic catalyst and a biomass including microalgae and water, a cooling device for cooling the product from a supercritical water gasification reactor at 70-80 degrees C, and a separator for separating the cooled product into a liquid phase product and a gas phase product. The supercritical water gasification reactor is operated at a temperature of 450-600 degrees C and a pressure of 200-300 bar using supercritical water. The device further comprises: a high pressure tubular reactor for preheating the biomass before introducing the biomass into the supercritical water gasification reactor; a pressure pump that is arranged in the high pressure tubular reactor and transfers the biomass to the supercritical water gasification reactor; an evaporator for heating the liquid product from the separator at 30-100 degrees C; a gas cleaning unit for removing the carbon dioxide from the gas product from the separator; a moisture absorption device that absorbs the remaining moisture content in the gas product; a syngas to liquid reactor that manufactures a Fisher-Tropsch reaction product from the gas product through a Fischer-Tropsch synthetic reaction using a non-precious metals catalyst; a condenser that cools the Fisher-Tropsch reaction product from the syngas to liquid reactor at 70-80 degrees C and separates the product into a Fischer-Tropsch reaction liquid product and a Fischer-Tropsch reaction gas product; a dehumidifying unit that comprises desiccant and absorbs the moisture content in the Fischer-Tropsch reaction gas product from the condenser; and a pressure controller that controls the pressure of the product from the refrigerator and is equipped between the refrigerator and the separator. The high pressure tubular reactor is operated at a temperature of 200-300 degrees C and a pressure of 200-300 bar. The syngas to liquid reactor is operated at a temperature of 200-300 degrees C and a pressure of 10-40 bar. The biomass has a moisture content of 10-65 wt.%. The microalgae comprise carbohydrate content of 5-40 wt.% and lipid content of 10-80 wt.%.