SEALING BODY AND BATTERY

A battery includes: a case including a cylindrical part, a bottom part that closes one end part of the cylindrical part, and an opening edge part continuous with the other end part of the cylindrical part; an electrode assembly housed in the cylindrical part; and a sealing body fixed to the opening edge so as to seal an opening of the opening edge part, in which the sealing body including a sealing plate made of a first metal and a terminal member made of a second metal different from the first metal and held by the sealing plate is used. The sealing plate includes a fixing part to which the terminal member is fixed, a peripheral edge part in an annular shape located at a peripheral edge, and a thin part formed between the fixing part and the peripheral edge part. The fixing part includes a protrusion part protruding from an outer surface of the sealing plate, and the protrusion part is bent inward such that a part of the terminal member is sandwiched between the fixing part and the protrusion part.