ENERGY STORAGE DEVICE

An energy storage device includes an electrode terminal including a plate-like terminal body and a shaft portion connected to the terminal body, and an upper insulating member disposed between the terminal body and the case, the upper insulating member having a through-hole through which the shaft portion penetrates. The upper insulating member has a sidewall portion disposed along an end surface of the terminal body. The sidewall portion is provided with a thin portion at a position on a side of a center point of the shaft portion in a direction orthogonal to an extending direction of the sidewall portion in a plan view.