Cylindrical battery

A cylindrical battery (10) is provided with: an electrode body (14) in which a positive electrode (11) and a negative electrode (12) are wound with a separator (13) interposed therebetween; a bottomed cylindrical outer tank (16) that accommodates the electrode body (14); a sealing body (17) that seals the opening of the outer can (16); and a gasket (28) that insulates the outer can (16) and the sealing body (17) from each other. The outer surface of the pad (28) is provided with one or more tip-narrowed grooves (51, 52) including tip-narrowed portions, the tips of which are narrowed toward the electrode body (15) side. 圆筒形电池(10)具备：电极体(14)，将正极(11)和负极(12)隔着分隔件(13)卷绕而成；有底筒状的外装罐(16)，容纳电极体(14)；封口体(17)，将外装罐(16)的开口封口；和衬垫(28)，将外装罐(16)和封口体(17)绝缘。在衬垫(28)的外表面设置1个以上的前端变细槽(51、52)，该前端变细槽(51、52)包含随着去往电极体(15)侧而前端变细的前端变细部。