A method for manufacturing an electrochemical cell, the electrochemical cell comprising: an electrochemical cell main body including: a positive electrode that is composed of a positive electrode active material and a positive electrode current collector provided with a metal terminal at an end portion thereof; a negative electrode that is composed of a negative electrode active material and a negative electrode current collector provided with a metal terminal at an end portion thereof; and an electrolyte filled between the positive electrode and the negative electrode; and an outer packaging body made of a packaging material formed by sequentially laminating at least a metal foil layer and a heat-sealable resin layer, the method comprising: housing the electrochemical cell main body in the outer packaging body so that tip ends of the metal terminals protrude to an outside; heat-sealing a peripheral edge portion of the outer packaging body; subsequently applying an impulse voltage for a time in the order of milliseconds, for example for 90 milliseconds, between one of the metal terminals and the metal foil layer; and performing an inspection as to whether or not there is an insulation failure based on a variation with time of a voltage held between the one of the metal terminals and the metal foil layer after the impulse voltage application is halted. an electrochemical cell main body including: a positive electrode that is composed of a positive electrode active material and a positive electrode current collector provided with a metal terminal at an end portion thereof; a negative electrode that is composed of a negative electrode active material and a negative electrode current collector provided with a metal terminal at an end portion thereof; and an electrolyte filled between the positive electrode and the negative electrode; and a positive electrode that is composed of a positive electrode active material and a positive electrode current collector provided with a metal terminal at an end portion thereof; a negative electrode that is composed of a negative electrode active material and a negative electrode current collector provided with a metal terminal at an end portion thereof; and an electrolyte filled between the positive electrode and the negative electrode; and an outer packaging body made of a packaging material formed by sequentially laminating at least a metal foil layer and a heat-sealable resin layer, the method comprising: housing the electrochemical cell main body in the outer packaging body so that tip ends of the metal terminals protrude to an outside; heat-sealing a peripheral edge portion of the outer packaging body; subsequently applying an impulse voltage for a time in the order of milliseconds, for example for 90 milliseconds, between one of the metal terminals and the metal foil layer; and performing an inspection as to whether or not there is an insulation failure based on a variation with time of a voltage held between the one of the metal terminals and the metal foil layer after the impulse voltage application is halted. housing the electrochemical cell main body in the outer packaging body so that tip ends of the metal terminals protrude to an outside; heat-sealing a peripheral edge portion of the outer packaging body; subsequently applying an impulse voltage for a time in the order of milliseconds, for example for 90 milliseconds, between one of the metal terminals and the metal foil layer; and performing an inspection as to whether or not there is an insulation failure based on a variation with time of a voltage held between the one of the metal terminals and the metal foil layer after the impulse voltage application is halted.