A rechargeable battery comprising: an electrode assembly formed by disposing an electrode having coated regions (111, 121) and uncoated tabs (112, 122) at opposite sides of a separator; a case accommodating the electrode assembly therein; a cap plate coupled to an opening of the case; and electrode terminals (51, 52) insert-molded into terminal holes (H1, H2) of the cap plate and connected to the uncoated tabs (112, 122), wherein the electrode terminal (51, 52) includes: an external terminal portion (511, 521) protruding outside of the cap plate; an internal terminal portion (512, 522) disposed within the cap plate and connected to the uncoated tabs (112, 122); and a connector (513, 523) connecting the external terminal portion (511, 521) and the internal terminal portion (512, 522), and disposed in the terminal hole (H1, H2) and insulated by a molding resin material wherein the external terminal portion (511, 521) and the internal terminal portion (512, 522) are integrally formed, the connector (513, 523) forms a step between a first thickness of the external terminal portion (511, 521) and a second thickness of the internal terminal portion (512, 522), to extend in a height direction intersecting with a plane of the cap, and the molding resin material seals the external terminal portion (511, 521) outside the terminal hole (H1, H2), seals the internal terminal portion (512, 522) inside the terminal hole (H1, H2), and seals the step within a thickness range of the cap plate, wherein the terminal hole (H1, H2) is formed with a first gap in a width direction of the cap plate, and is formed with a second gap that is larger than the first gap in a longitudinal direction that intersects the width direction to be spaced apart from the electrode terminal (51, 52), and wherein the external portion of the electrode terminal (51, 52) has a thickness that is smaller than the first gap in the width direction, and has a width that is smaller than the second gap and larger than the thickness in the longitudinal direction. an electrode assembly formed by disposing an electrode having coated regions (111, 121) and uncoated tabs (112, 122) at opposite sides of a separator; a case accommodating the electrode assembly therein; a cap plate coupled to an opening of the case; and electrode terminals (51, 52) insert-molded into terminal holes (H1, H2) of the cap plate and connected to the uncoated tabs (112, 122), wherein the electrode terminal (51, 52) includes: an external terminal portion (511, 521) protruding outside of the cap plate; an internal terminal portion (512, 522) disposed within the cap plate and connected to the uncoated tabs (112, 122); and a connector (513, 523) connecting the external terminal portion (511, 521) and the internal terminal portion (512, 522), and disposed in the terminal hole (H1, H2) and insulated by a molding resin material wherein the external terminal portion (511, 521) and the internal terminal portion (512, 522) are integrally formed, the connector (513, 523) forms a step between a first thickness of the external terminal portion (511, 521) and a second thickness of the internal terminal portion (512, 522), to extend in a height direction intersecting with a plane of the cap, and the molding resin material seals the external terminal portion (511, 521) outside the terminal hole (H1, H2), seals the internal terminal portion (512, 522) inside the terminal hole (H1, H2), and seals the step within a thickness range of the cap plate, wherein the terminal hole (H1, H2) is formed with a first gap in a width direction of the cap plate, and is formed with a second gap that is larger than the first gap in a longitudinal direction that intersects the width direction to be spaced apart from the electrode terminal (51, 52), and wherein the external portion of the electrode terminal (51, 52) has a thickness that is smaller than the first gap in the width direction, and has a width that is smaller than the second gap and larger than the thickness in the longitudinal direction. an external terminal portion (511, 521) protruding outside of the cap plate; an internal terminal portion (512, 522) disposed within the cap plate and connected to the uncoated tabs (112, 122); and a connector (513, 523) connecting the external terminal portion (511, 521) and the internal terminal portion (512, 522), and disposed in the terminal hole (H1, H2) and insulated by a molding resin material wherein the external terminal portion (511, 521) and the internal terminal portion (512, 522) are integrally formed, the connector (513, 523) forms a step between a first thickness of the external terminal portion (511, 521) and a second thickness of the internal terminal portion (512, 522), to extend in a height direction intersecting with a plane of the cap, and the molding resin material seals the external terminal portion (511, 521) outside the terminal hole (H1, H2), seals the internal terminal portion (512, 522) inside the terminal hole (H1, H2), and seals the step within a thickness range of the cap plate, wherein the terminal hole (H1, H2) is formed with a first gap in a width direction of the cap plate, and is formed with a second gap that is larger than the first gap in a longitudinal direction that intersects the width direction to be spaced apart from the electrode terminal (51, 52), and wherein the external portion of the electrode terminal (51, 52) has a thickness that is smaller than the first gap in the width direction, and has a width that is smaller than the second gap and larger than the thickness in the longitudinal direction.