To provide an antenna which can be made compact easily even if there are a plurality of spiral antenna elements, and to provide an antenna device including the same.

An antenna includes a rod-like support (core rod 45), a first spiral antenna element (antenna winding 20) wound around the axis (axis line 47) of the support, and a second spiral antenna element (antenna winding 30) wound around the axis in the opposite direction to the first spiral antenna element while overlapping via the first spiral antenna element and an insulator (insulation material 50). An antenna device including the antenna is also provided. The first spiral antenna element and the second spiral antenna element are connected electrically at a root 46 of the support.