A secondary battery has a conductive member, a current interrupt device, and a pressure-sensitive member. The conductive member has an opening on an outer side of the secondary battery. The current interrupt device has a reverse plate connected with the conductive member and is provided inside the secondary battery. The pressure-sensitive member seals the opening, and a state of the pressure-sensitive member changes in accordance with an increase in pressure of a space surrounded by the reverse plate and the conductive member.