A current interruption device disclosed in the present specification includes: a first conductive member and a second conductive member that are facing each other; an insulating seal member disposed therebetween; and an insulating cover accommodating the first conductive member, the second conductive member, and the seal member. The seal member separates a space between the first and second conductive members into an inner space and an outer space which communicates with the space within the casing. In a plan view, the seal member is positioned in an entire area outside of contact portions of the seal member with the first and second conductive members within a range where the first and second conductive members are facing each other. The cover is disposed along outer circumferential edges of the first and second conductive members, and the seal member is in contact with the cover.