A battery module according to an embodiment of the present invention comprises: a battery cell stack comprising a plurality of battery cells stacked together; a module frame in which the battery cell stack is accommodated; and a flame discharge frame arranged to cover one surface of the module frame. The flame discharge frame is shaped to be indented in the opposite direction to the direction in which the one surface of the module frame is positioned. A passage portion is formed between the flame discharge frame and the one surface of the module frame, and the passage portion extends to a flame outlet formed in the flame discharge frame.