An energy storage module (100, 200) comprising: a plurality of battery cells arranged in a length direction such that long side surfaces of adjacent ones of the battery cells face one another; a plurality of insulation spacers (130, 230), at least one of the insulation spacers (130, 230) being between the long side surfaces of each adjacent pair of the battery cells; a cover member (110, 210) comprising an internal receiving space configured to accommodate the battery cells and the insulation spacers (130, 230); a top plate coupled to a top of the cover member (110, 210), the top plate comprising ducts (141, 241) respectively corresponding to vents of the battery cells and having opening holes (143, 243) respectively corresponding to the insulation spacers (130, 230); a top cover (160, 260) coupled to a top of the top plate (140, 240) and having discharge holes (161, 261) respectively corresponding to the ducts (141, 241); and an extinguisher sheet (150, 250) between the top cover (160, 260) and the top plate (140, 240), the extinguisher sheet (150, 250) being configured to emit a fire extinguishing agent at a temperature exceeding a reference temperature, wherein the top cover (160, 260) comprises protrusion parts (162, 262) on a bottom surface (160b, 260b) thereof, the protrusion parts (162, 262) covering an exhaust region and being coupled to an exterior of each of the ducts (141, 241), and each of the insulation spacers (130, 230) comprises a heat-insulating first sheet (131a, 231a) and flame-retardant or non-combustible second sheets (131b, 231b) respectively adhered to opposite surfaces of the first sheet (131a, 231a) by an adhesion member (131c, 231c), and wherein the long side surfaces of the adjacent battery cells are spaced apart from each other by a first distance, and wherein a thickness of each of the insulation spacers (130, 230) is less than 50% of the first distance. a plurality of battery cells arranged in a length direction such that long side surfaces of adjacent ones of the battery cells face one another; a plurality of insulation spacers (130, 230), at least one of the insulation spacers (130, 230) being between the long side surfaces of each adjacent pair of the battery cells; a cover member (110, 210) comprising an internal receiving space configured to accommodate the battery cells and the insulation spacers (130, 230); a top plate coupled to a top of the cover member (110, 210), the top plate comprising ducts (141, 241) respectively corresponding to vents of the battery cells and having opening holes (143, 243) respectively corresponding to the insulation spacers (130, 230); a top cover (160, 260) coupled to a top of the top plate (140, 240) and having discharge holes (161, 261) respectively corresponding to the ducts (141, 241); and an extinguisher sheet (150, 250) between the top cover (160, 260) and the top plate (140, 240), the extinguisher sheet (150, 250) being configured to emit a fire extinguishing agent at a temperature exceeding a reference temperature, wherein the top cover (160, 260) comprises protrusion parts (162, 262) on a bottom surface (160b, 260b) thereof, the protrusion parts (162, 262) covering an exhaust region and being coupled to an exterior of each of the ducts (141, 241), and each of the insulation spacers (130, 230) comprises a heat-insulating first sheet (131a, 231a) and flame-retardant or non-combustible second sheets (131b, 231b) respectively adhered to opposite surfaces of the first sheet (131a, 231a) by an adhesion member (131c, 231c), and wherein the long side surfaces of the adjacent battery cells are spaced apart from each other by a first distance, and wherein a thickness of each of the insulation spacers (130, 230) is less than 50% of the first distance.