A preferred terminal structure comprises a base material; an electrode formed on the base material; an insulating covering layer formed on the base material and on the electrode and having an opening exposing at least part of the electrode; an under bump metal layer containing Ni, formed in a region in the opening on the electrode so that an upper surface of the metal layer is at a position lower than an upper surface of the insulating covering layer in a peripheral edge portion of the opening; and a dome-shaped bump containing Sn and Ti, formed in a region in the opening on the under bump metal layer, wherein an end portion of a boundary between the under bump metal layer and the bump is in contact with an inner wall of the opening portion in the insulating covering layer.