An antenna device (10) includes a feed element (11) including a first portion (111) and a second portion (112) and a non-feed element (12) including a plurality of folded back portions (121 to 125). The width (W2) of the second portion of the feed element is rendered larger than the width (W3) of the non-feed element, and at least the second portion of the feed element is configured to be coupled to the plurality of folded back portions of the non-feed element.