A sealing member (positive electrode first sealing member) disposed between a terminal (positive electrode terminal), which is provided on a case of an energy storage device, and the case or between a current collector (positive electrode current collector), which is electrically connected with the terminal, and the case. The sealing member includes a first surface (bottom surface) which faces the case and a second surface (bottom surface) which is opposite to the first surface and faces the terminal or the current collector. A first protrusion is formed on the first surface, the first protrusion surrounding a shaft portion of the terminal. A second protrusion is formed on the second surface, the second protrusion surrounding the shaft portion of the terminal. A protrusion amount of the first protrusion is different from a protrusion amount of the second protrusion.