BATTERY PACK

Provided is a battery pack with an improved sealing force, the battery pack including: a lower case having a space therein and having a groove portion formed to extend along a certain width of an outer top surface; an upper case arranged on the lower case; a battery unit accommodated in an internal space of the lower case and including a plurality of battery cells; and a sealing member inserted into the groove portion to be located between the upper case and the lower case, wherein a cross-sectional shape thereof has an upper surface, a lower surface, and a side surface connecting the upper surface to the lower surface, the upper surface is formed as a curved surface convexed toward the upper case, and a protrusion portion forming a step with the upper surface is located at the side surface.