A secondary battery according to an embodiment includes a container having a pouring hole through which an electrolyte is poured, and housing the electrolyte, poured through the pouring hole, together with an electrode body; and a sealing lid fixed to the container and closing the pouring hole. The container has a plurality of grooves extending in parallel along the outer edge of the pouring hole, in a predetermined region that surrounds the periphery of the pouring hole, and the sealing lid is provided on the plurality of grooves in such a manner as to close the pouring hole and is fixed to the container.