A method for manufacturing an electrochemical cell includes housing a main cell body in an outer packaging body of packaging material formed by laminating a metal foil layer and a heat-sealable resin layer, provided the tip ends of a first metal terminal and a second metal terminal are protruding outside the outer packaging body, heat-sealing a peripheral edge portion of the outer packaging body so the outer packaging body has the first and second terminals protruding; applying a voltage between the first terminal and the foil layer or between the second terminal and the foil layer; and inspecting for insulation failure from a short circuit between the first or second terminal and the foil layer or from a crack in the heat-sealable resin layer, based on a variation of a voltage held between the one of the metal terminals and the metal foil layer after halting the voltage.