VENTING DEVICE AND METHOD FOR MANUFACTURING SAME

To solve the above problem, a venting device inserted into a sealing part of a pouch of a secondary battery according to the present invention includes: a housing inserted between both surfaces of the sealing part and sealed together with the sealing part; a sheet which made of a metal and formed in the housing and through which a passage allowing the inside and outside of the pouch to communicate with each other passes; and a ball contacting or spaced apart from the sheet at an outlet-side of the passage to open and close the passage, wherein, in the sheet, an edge of an inner circumference of a surface of the outlet-side of the passage is chamfered or filleted so as to face the ball, and the sheet includes: a surface treatment layer formed on the chamfered or filleted one surface; and a polymer layer made of a polymer and fused to the surface treatment layer.