Disclosed is a battery pack including a battery module array including battery modules arranged in two or more rows, a pair of side support members (a front support member and a rear support member) configured to respectively support a front and a rear of the battery module array, lower end support members configured to support a lower end of the battery module array, two or more first upper mounting members coupled to upper ends of the side support members and to lower ends of the inverted battery modules, a second upper mounting member configured to vertically intersect the first upper mounting members, the second upper mounting member being coupled to upper ends of the first upper mounting members, and a rear mounting member located at a rear of the battery module array.