To provide an electromotive force inspecting device for battery capable of being manufactured in different dimension and various design.

A contact part as an electrode is provided at diagonal positions of a film-like substrate, and a conductive layer is formed on a diagonal of the film-like substrate so that a long side of the film-like substrate is shortened while maintaining the necessary and minimum length. The conductive layer can be formed in a route displaced from the diagonal so as to secure a space in the film-like substrate, and design is elaborated so as to provide a visually interesting device.