Pouch Type Secondary Battery

A secondary battery includes an electrode assembly, a pouch type case including an accommodation portion for accommodating the electrode assembly and a sealing portion for sealing the accommodation portion, an electrode lead connected to the electrode assembly and protruding to the outside of the pouch type case via the sealing portion, a lead film disposed between the electrode lead and the pouch type case, and a gas guide portion disposed between the electrode lead and the lead film. The gas guide portion includes a first layer having a modified polyolefin resin in contact with the electrode lead, and a second layer disposed on the first layer.