A battery pack comprising: a battery cell assembly in which a plurality of chargeable and dischargeable battery cells are stacked; and a pair of cooling members (210, 220) configured to eliminate heat generated during charging and discharging of the battery cells, wherein the cooling members (210, 220) include first and second cooling members (210, 220) positioned on first and second surfaces of the battery cell assembly perpendicular to the stacking direction of the battery cells, an inner surface of each of the first cooling member and the second cooling member is formed with a thermal contact portion (211, 221) with a shape of being in close contact with an outer surface of each of the first and second surfaces of the battery cell assembly for thermal conduction, the battery cells are stacked and arranged to form the battery cell assembly in a state in which adjacent battery cells directly face each other, the thermal contact portions (211, 221) face each other with the battery cell assembly therebetween, and the thermal contact portion formed at the first cooling member and the thermal contact portion formed at the second cooling member respectively protrude in directions of the second cooling member and the first cooling member, the thermal contact portion (211, 221) of the cooling member (210, 220) is formed to have a shape of which opposite side end portions of the battery cells are inserted therein and are in close contact therewith, the battery cell is a pouch-type battery cell in which an electrode assembly is embedded in an accommodating portion of a pouch-type battery case, and an outer circumference of the accommodating portion is formed of a heat fusion sealing portion, the thermal contact portion (211, 221) of the cooling member (210, 220) is formed to have a shape that allows to closely contact with the heat fusion sealing portion of the pouch-type battery cell and to closely contact with an outer lateral wall of the accommodating portion adjacent to the heat fusion sealing portion, and characterized in that a thermal conduction member configured to improve thermal conduction is additionally disposed at an interface between the thermal contact portion (211, 221) of the cooling members (210, 220) and the battery cell assembly to eliminate air existing at the interface between the thermal contact portion (211, 221) and the battery cell assembly. a battery cell assembly in which a plurality of chargeable and dischargeable battery cells are stacked; and a pair of cooling members (210, 220) configured to eliminate heat generated during charging and discharging of the battery cells, wherein the cooling members (210, 220) include first and second cooling members (210, 220) positioned on first and second surfaces of the battery cell assembly perpendicular to the stacking direction of the battery cells, an inner surface of each of the first cooling member and the second cooling member is formed with a thermal contact portion (211, 221) with a shape of being in close contact with an outer surface of each of the first and second surfaces of the battery cell assembly for thermal conduction, the battery cells are stacked and arranged to form the battery cell assembly in a state in which adjacent battery cells directly face each other, the thermal contact portions (211, 221) face each other with the battery cell assembly therebetween, and the thermal contact portion formed at the first cooling member and the thermal contact portion formed at the second cooling member respectively protrude in directions of the second cooling member and the first cooling member, the thermal contact portion (211, 221) of the cooling member (210, 220) is formed to have a shape of which opposite side end portions of the battery cells are inserted therein and are in close contact therewith, the battery cell is a pouch-type battery cell in which an electrode assembly is embedded in an accommodating portion of a pouch-type battery case, and an outer circumference of the accommodating portion is formed of a heat fusion sealing portion, the thermal contact portion (211, 221) of the cooling member (210, 220) is formed to have a shape that allows to closely contact with the heat fusion sealing portion of the pouch-type battery cell and to closely contact with an outer lateral wall of the accommodating portion adjacent to the heat fusion sealing portion, and characterized in that a thermal conduction member configured to improve thermal conduction is additionally disposed at an interface between the thermal contact portion (211, 221) of the cooling members (210, 220) and the battery cell assembly to eliminate air existing at the interface between the thermal contact portion (211, 221) and the battery cell assembly.