Battery Pack

Disclosed is a battery pack in which a seating recess is provided in a horizontal frame so that connection members pass through the horizontal frame through the seating recess, thereby maximizing a height of the horizontal frame. A vertical frame cover is provided in a vertical frame to secure a height of the vertical frame side in each module space. A sealing member is provided in the seating recess to seal the seating recess. A double shielding structure, including a module space cover shielding each module space and a battery pack cover shielding a battery pack housing as a whole, is provided to maximize airtightness of the battery pack.