A current interruption device is provided with a first conducting member that is fixed to a casing, a second conducting member that is disposed at a position opposed to the first conducting member, a first deforming member, and a second deforming member. The first deforming member makes contact with the second conducting member when pressure in the casing is equal to or less than a predetermined value, and is configured not to make contact with the second conducting member when the pressure in the casing exceeds the predetermined value. The second deforming member is provided with a projection in a shape projecting toward a center portion of the second conducting member. A restricting structure that restricts a movement of the first deforming member is provided on the first conducting member. A restricting structure that restricts a movement of the second deforming member is provided on the second conducting member.