The present disclosure provides an elastic interposer including a flexible substrate and a conductive device. The flexible substrate includes multiple circuits, of which first terminals are exposed on a first surface of the flexible substrate and show a first pattern, and of which second terminals are exposed on a second surface of the flexible substrate and show a second pattern different from the first pattern. The conductive device includes a first flexible conductive element and a second flexible conductive element. The first flexible conductive element is disposed on the first surface of the flexible substrate, and includes multiple first elastic conductive portions electrically connected to the first terminals of the circuits. The second flexible conductive element is disposed on the second surface of the flexible substrate, and includes multiple second elastic conductive portions electrically connected to the second terminals of the circuits.