CYLINDRICAL BATTERY

Provided is a cylindrical battery that has improved safety and also suppresses deformation of a bottom part. According to one aspect of the present disclosure, a cylindrical battery comprises an electrode body, an electrolyte, an outer can that is a bottomed cylinder that houses the electrode body and the electrolyte, and a sealing body that closes an opening part of the outer can. A bottom part of the outer can has a first groove that forms a polygon and a plurality of second grooves that respectively extend from the plurality of vertices of the polygon toward the outside.