A first radiating element and a second radiating element each have a first extending portion protruding from a region where a ground conductor is formed to a non-ground-conductor region, and a second extending portion extending parallel with a boundary of the ground-conductor region and the non-ground-conductor region. The first radiating element and the second radiating element are arranged such that an open end of the second extending portion of the first radiating element and an open end of a second extending portion of the second radiating element face each other. A parasitic element is formed on a side of the second radiating element distant from the region (where the ground conductor is formed. A parasitic element is formed along the first radiating element. With this configuration, an antenna device is realized which has gain in two frequency bands and has forward directivity.