A battery module, comprising: a cell stack formed by stacking a plurality of battery cells; a bus bar frame assembly including a bus bar frame configured to cover one longitudinal end and the other longitudinal end of the cell stack and a plurality of bus bars fixed on the bus bar frame and electrically connected to the battery cells; and an outer terminal connected to the bus bar, wherein the battery cell includes an electrode assembly, a pair of electrode leads connected to the electrode assembly and extending in opposite directions along a longitudinal direction (Y-axis direction) of the battery cell, and a cell case configured to accommodate the electrode assembly and sealed to expose the electrode lead to the outside, the pair of electrode leads are formed at locations offset to one side from a center of the battery cell in a width direction (Z-axis direction) of the battery cell, to be offset downward from a center of the cell stack in a height direction (Z-axis direction) of the cell stack, and the outer terminal is disposed in the space formed above the electrode lead due to the offsetting of the electrode lead, and further comprising: a FPCB assembly including a first FPCB extending along a longitudinal direction of the cell stack to cover at least a portion of an upper surface of the cell stack, a second FPCB extending from both longitudinal ends of the first FPCB and electrically connected to the bus bars, and a pair of temperature sensors mounted to both longitudinal ends of the first FPCB, wherein the first FPCB has a temperature sensor placing portion formed by cutting a part of the first FPCB, wherein one of both longitudinal ends of the temperature sensor placing portion is formed as a fixed end and the other is formed as a free end, and both widthwise ends of the temperature sensor placing portion are formed as free ends by cutting, wherein the temperature sensor is mounted to the upper surface of the temperature sensor placing portion, whereby the temperature sensor is installed at positions corresponding to both longitudinal ends of the cell stack, and wherein the temperature sensor placing portion is located at the center of the cell stack in the width direction. a cell stack formed by stacking a plurality of battery cells; a bus bar frame assembly including a bus bar frame configured to cover one longitudinal end and the other longitudinal end of the cell stack and a plurality of bus bars fixed on the bus bar frame and electrically connected to the battery cells; and an outer terminal connected to the bus bar, wherein the battery cell includes an electrode assembly, a pair of electrode leads connected to the electrode assembly and extending in opposite directions along a longitudinal direction (Y-axis direction) of the battery cell, and a cell case configured to accommodate the electrode assembly and sealed to expose the electrode lead to the outside, the pair of electrode leads are formed at locations offset to one side from a center of the battery cell in a width direction (Z-axis direction) of the battery cell, to be offset downward from a center of the cell stack in a height direction (Z-axis direction) of the cell stack, and the outer terminal is disposed in the space formed above the electrode lead due to the offsetting of the electrode lead, and further comprising: a FPCB assembly including a first FPCB extending along a longitudinal direction of the cell stack to cover at least a portion of an upper surface of the cell stack, a second FPCB extending from both longitudinal ends of the first FPCB and electrically connected to the bus bars, and a pair of temperature sensors mounted to both longitudinal ends of the first FPCB, wherein the first FPCB has a temperature sensor placing portion formed by cutting a part of the first FPCB, wherein one of both longitudinal ends of the temperature sensor placing portion is formed as a fixed end and the other is formed as a free end, and both widthwise ends of the temperature sensor placing portion are formed as free ends by cutting, wherein the temperature sensor is mounted to the upper surface of the temperature sensor placing portion, whereby the temperature sensor is installed at positions corresponding to both longitudinal ends of the cell stack, and wherein the temperature sensor placing portion is located at the center of the cell stack in the width direction. a FPCB assembly including a first FPCB extending along a longitudinal direction of the cell stack to cover at least a portion of an upper surface of the cell stack, a second FPCB extending from both longitudinal ends of the first FPCB and electrically connected to the bus bars, and a pair of temperature sensors mounted to both longitudinal ends of the first FPCB, wherein the first FPCB has a temperature sensor placing portion formed by cutting a part of the first FPCB, wherein one of both longitudinal ends of the temperature sensor placing portion is formed as a fixed end and the other is formed as a free end, and both widthwise ends of the temperature sensor placing portion are formed as free ends by cutting, wherein the temperature sensor is mounted to the upper surface of the temperature sensor placing portion, whereby the temperature sensor is installed at positions corresponding to both longitudinal ends of the cell stack, and wherein the temperature sensor placing portion is located at the center of the cell stack in the width direction.