A battery comprising: a battery element ; a housing body ; and a valve device , wherein the housing body is constituted by at least one laminate and includes an interior space (S1) in which the battery element is housed, a first housing portion that covers the interior space (S1) from a first side in a thickness direction of the battery , and a second housing portion that covers the interior space (S1) from a second side that is opposite to the first side in the thickness direction of the battery , the valve device is attached to the housing body and can make the interior space (S1) of the housing body be in communication with an external space, a joined edge portion is formed in the housing body as a result of the first housing portion and the second housing portion being fused along respective peripheral edge portions, the valve device is at least partially sandwiched between the first housing portion and the second housing portion in the joined edge portion , the first housing portion includes a bulge portion that is arranged on an inner side of an inner edge (P2) of the joined edge portion and bulges toward the first side in the thickness direction of the battery with respect to the joined edge portion , the valve device includes a valve mechanism and a housing in which the valve mechanism is formed, the valve mechanism being configured to discharge gas generated in the interior space (S1) of the housing body to the external space outside the housing body , and an inner end part of the housing includes an opening that is in communication with the interior space (S1) of the housing body in a closed state of the valve mechanism, characterised in that an inner end of the valve device is located on an outer side of an outer edge (P3) of the bulge portion and reaches at least the inner edge (P2) of the joined edge portion . a battery element ; a housing body ; and a valve device , wherein the housing body is constituted by at least one laminate and includes an interior space (S1) in which the battery element is housed, a first housing portion that covers the interior space (S1) from a first side in a thickness direction of the battery , and a second housing portion that covers the interior space (S1) from a second side that is opposite to the first side in the thickness direction of the battery , the valve device is attached to the housing body and can make the interior space (S1) of the housing body be in communication with an external space, a joined edge portion is formed in the housing body as a result of the first housing portion and the second housing portion being fused along respective peripheral edge portions, the valve device is at least partially sandwiched between the first housing portion and the second housing portion in the joined edge portion , the first housing portion includes a bulge portion that is arranged on an inner side of an inner edge (P2) of the joined edge portion and bulges toward the first side in the thickness direction of the battery with respect to the joined edge portion , the valve device includes a valve mechanism and a housing in which the valve mechanism is formed, the valve mechanism being configured to discharge gas generated in the interior space (S1) of the housing body to the external space outside the housing body , and an inner end part of the housing includes an opening that is in communication with the interior space (S1) of the housing body in a closed state of the valve mechanism, characterised in that an inner end of the valve device is located on an outer side of an outer edge (P3) of the bulge portion and reaches at least the inner edge (P2) of the joined edge portion . <EOS>