Secondary battery with sandwiched portion of coupling wiring line

A secondary battery includes an outer package member, a battery device, an external terminal, and a coupling wiring line. The battery device is contained inside the outer package member, and includes a first electrode and a second electrode. The external terminal is attached to the outer package member and insulated from the outer package member. The coupling wiring line is coupled to each of the first electrode and the external terminal. A portion of the coupling wiring line is insulated from each of the outer package member and the second electrode, and is sandwiched by the outer package member and the battery device.