Disclosed is a battery pack with an improved structure to support a torque applied to a terminal bolt when a nut is coupled to the terminal bolt which is exposed out of the battery pack and serves as a connection terminal. The battery pack includes a cell assembly having a plurality of secondary batteries, a pack housing having an inner space to accommodate the cell assembly therein, a terminal bolt configured to protrude out of the pack housing, a center plate located at an upper portion of the cell assembly in the inner space of the pack housing and having an insert groove formed therein, and a bus bar having one end electrically connected to an electrode terminal of the cell assembly and the other end connected to the terminal bolt by contact, the bus bar being inserted into the insert groove of the center plate.