A pouch case of the present disclosure includes an inner resin layer, a metallic layer, and an outer resin layer, wherein the resin layer(s) include(s) a foaming activator containing an isocyanate-based compound and a polyol compound. Accordingly, since the pouch case includes the inner resin layer and/or the outer resin layer including the foaming activator, when moisture or the like is permeated thereto due to an external factor, a protective layer including urethane-based foam is formed in the outer resin layer or between the inner resin layer and an electrode assembly in a short time, so that the pouch case and the electrode assembly may be protected, moisture which is permeable into the electrode assembly may be blocked, and separator cracking also may be prevented. Accordingly, explosion which may be caused by moisture permeation, separator cracking, or a short circuit by contact between the pouch case and the electrode assembly, or the like, may be prevented, and stability of a pouch type secondary battery may thus be ensured.