A secondary battery internal gas-collecting apparatus for collecting gas generated in a secondary battery including an electrode assembly and a rigid battery case accommodating the electrode assembly therein, the apparatus comprising: a pressing jig part for pressing one surface of the battery case, wherein the pressing jig part is provided with a gas collecting pipe through which the gas generated inside the battery case flows, characterized by a sealing part inserted between the pressing jig part and the one surface of the battery case; and a fixing unit for fixing the pressing jig part and the battery case in a state that the sealing part is inserted between the pressing jig part and the battery case, wherein the one surface of the battery case is a first surface, and the other surface of the battery case facing the first surface is a second surface, and the fixing unit comprises: a supporting jig part contacting the second surface to support the secondary battery; a first plate to which the pressing jig part is fixed and which faces the first surface at a position spaced apart therefrom; a second plate to which the supporting jig part is fixed and which faces the second surface at a position spaced apart therefrom; and a pillar part coupled to and fixing the first plate and the second plate so that the first plate and the second plate maintain a certain distance from each other, wherein the pillar part extends in a direction perpendicular to the first surface. a pressing jig part for pressing one surface of the battery case, wherein the pressing jig part is provided with a gas collecting pipe through which the gas generated inside the battery case flows, characterized by a sealing part inserted between the pressing jig part and the one surface of the battery case; and a fixing unit for fixing the pressing jig part and the battery case in a state that the sealing part is inserted between the pressing jig part and the battery case, wherein the one surface of the battery case is a first surface, and the other surface of the battery case facing the first surface is a second surface, and the fixing unit comprises: a supporting jig part contacting the second surface to support the secondary battery; a first plate to which the pressing jig part is fixed and which faces the first surface at a position spaced apart therefrom; a second plate to which the supporting jig part is fixed and which faces the second surface at a position spaced apart therefrom; and a pillar part coupled to and fixing the first plate and the second plate so that the first plate and the second plate maintain a certain distance from each other, wherein the pillar part extends in a direction perpendicular to the first surface. a supporting jig part contacting the second surface to support the secondary battery; a first plate to which the pressing jig part is fixed and which faces the first surface at a position spaced apart therefrom; a second plate to which the supporting jig part is fixed and which faces the second surface at a position spaced apart therefrom; and a pillar part coupled to and fixing the first plate and the second plate so that the first plate and the second plate maintain a certain distance from each other, wherein the pillar part extends in a direction perpendicular to the first surface.