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 which is fixed to the container and is closing the pouring hole. The sealing lid has a welding mark existing in a ring shape with a depth through the sealing lid to a lid body of the container, and an inner circumferential side molten mark existing in a ring shape overlapping with the welding mark, on the inner circumferential side of the welding mark in the sealing lid, with a depth corresponding to the thickness of the sealing lid.