A power storage device includes positive electrodes, negative electrodes separators each of which is located between a positive electrode and a negative electrode and insulates the positive electrode and the negative electrode from each other, and an electrode assembly, which is configured by stacking the positive electrodes, the negative electrodes, and the separators. The power storage device further includes an insulating member including sandwiching portions. Each sandwiching portion is formed by two insulating portions that sandwich a positive electrode non-application portion from both sides in the stacking direction of the electrode assembly. When viewed in the stacking direction of the electrode assembly, each insulating portion is arranged at least between a positive electrode border and a negative electrode border.