The battery module, according to the present invention, comprises: a cell assembly including a plurality of secondary batteries and having a fluid path formed between the secondary batteries; an inlet duct located at one side surface of the cell assembly so as to cover the one side surface of the cell assembly, and having an inlet port such that the fluid introduced through the inlet port flows into the fluid path; an outlet duct located at the other side surface of the cell assembly so as to cover the other side surface of the cell assembly, and having an outlet port such that the fluid discharged from the fluid path flows out through the outlet port; and an entrance cover provided to at least one of the inlet port and the outlet port, and having a plurality of ribs formed in a plate shape and slantingly arranged at a predetermined angle in the direction in which the inner and outer directions of the ribs are parallel to the ground, wherein at least one of the plurality of ribs has at least one of the inner and outer ends, which is bent.