Abstract: A non-destructive inspection method of detecting defects in a pouch-type secondary battery is disclosed. The defects are due to a crack or weld condition of an electrode sealed with a pouch. The method is used in a manufacturing process of the pouch-type secondary battery, where the manufacturing process includes an electrode tab pre-welding process; an electrode tab main-welding process; and a packing process. The method can include a first crack condition inspecting operation; a second crack condition inspecting operation; and a weld condition inspecting operation. The first crack condition inspecting operation inspects a first crack condition of the electrode tabs which occurs in the electrode tab pre-welding process. The second crack condition inspecting operation inspects a second crack condition of the electrode tabs, which occurs in the electrode tab main-welding process. The weld condition inspecting operation inspects a weld condition of the electrode tabs.