SEALED BATTERY

A sealed battery as an example of an embodiment is provided with an electrode body to which an electrode tab is connected, a closed-end cylindrical exterior housing can which houses the electrode body, and a sealing body that seals an opening of the exterior housing can. The sealing body includes a rupture disk. The rupture disk has a curved first thin-walled portion and a first valve portion surrounded by a straight-line portion connecting both ends of the first thin-walled portion. The first valve portion has a protruding section protruding toward the electrode body, the electrode tab is joined to a side surface of the protruding section, and at least a part of a joint surface between the electrode tab and the protruding section is disposed on a plane crossing the straight-line portion.