Disclosed is a battery container, which may stably support a plurality of battery modules received in the battery container and facilitate the stacking and separation of the battery modules, a sub-battery container used therein, and a battery pack using the same. The sub-battery container, includes two side plates standing to face each other at both side walls of the sub-battery container; and horizontal support bars disposed in parallel and so that both longitudinal ends of the horizontal support bars are coupled to the opposing corners of the two side plates, wherein the horizontal support bars include an upper horizontal support bar and a lower horizontal support bar, and the lower horizontal support bar and the upper horizontal support bar have uneven portions capable of coupling to each other at the bottom of the lower horizontal support bar and at the top of the upper horizontal support bar.