A battery case for a secondary battery according to an embodiment of the present invention can include a cup part having an accommodation space configured to accommodate an electrode assembly in which electrodes and separators are stacked; a sealing part extending to the outside of the cup part; a gas discharge part attached to a hole which is formed to be punched in at least one of the cup part or the sealing part from the outside and through which a gas passes; and a coating part applied to an inner circumferential surface of the hole and having electrolyte resistance, wherein the gas discharge part includes: a gas discharge layer through which the gas passes; and an outer functional layer formed on an outer surface of the gas discharge layer and having a hydrophobic property.