A feed radiation electrode including two branched radiation electrodes is provided on the surface of a substrate. Non-feed radiation electrodes are provided on both sides of the feed radiation electrode and near the branched radiation electrodes. The branched radiation electrode and the non-feed radiation electrode are double-resonated in the same frequency band. The branched radiation electrode and the non-feed radiation electrode are double-resonated in the same frequency band which is higher than that of the branched radiation electrode and the non-feed radiation electrode.