A method of manufacturing an electric power storage device includes a connection step of connecting an exposed portion, which is provided at one end in a direction of width of an electrode and constructed without a composite material layer being provided in a current collector, and a collector terminal provided on an outer side relative to the exposed portion in the direction of width of the electrode to each other. In the connection step, while a metal layer composed of a second metal higher in melting point than a first metal which forms the collector terminal lies between the exposed portion and the collector terminal, at least a portion of contact of the collector terminal with the metal layer is irradiated with energy.