A contact connection structure includes a first terminal including a first contact portion including an indent and a second terminal including a second contact portion including a contact face that makes contact with the indent. The indent includes a first arc face having the first curvature center extending on a first line, the contact face includes a second arc face having a curvature different from the curvature of the first arc face, the second curvature center of the second arc face extending on a second line perpendicular to the first line. The first arc face and the second arc face make contact with each other by an elliptic region. The direction of one of the first line and the second line is the direction of the long axis of the elliptic region, and the direction of the other line is a direction of the short axis of the elliptic region.