An antenna as an embodiment of the present invention is provided with an exciting element and a plurality of non-exciting elements. In a plan view, the exciting element includes a central region having a feeding point and at least three extending regions that extend radially from the central region. In the plan view, each non-exciting element includes a short circuit region having a short circuit point and a power receiving region located at a position where it is allowed to be capacitively coupled with corresponding one of the extending regions. In the plan view, a current path from the short circuit region to the power receiving region in each non-exciting element has a vertical component with respect to the extending direction of the corresponding one of the extending regions.