A secondary battery includes an outer package member, a battery device, a wiring member, and a sealing member. The outer package member has flexibility and has an opening. The battery device is accommodated inside the outer package member. The wiring member extends from an inside of the outer package member to an outside of the outer package member via the opening. The wiring member is coupled to the battery device. The sealing member has an insulating property. The sealing member extends along the wiring member from the inside of the outer package member at least to the opening, and is interposed between the battery device and the wiring member. The sealing member is configured to seal the opening.