Abstract: Antenna device (1) includes substrate (2) having first surface (21), antenna element (3), circuit element (4) and first pattern (6) formed of metal, antenna element (3) is arranged on first surface (21), circuit element (4) is soldered to first surface (21) and electrically connected to antenna element (3), first pattern (6) is arranged between antenna element (3) and circuit element (4) on first surface (21), a distance between antenna element (3) and first pattern (6) is a length equal to or larger than a width of antenna element. In this arrangement, antenna device (1) in which substrate (2) between antenna element (3) and circuit element (4) is reinforced by first pattern (6), and warping of substrate (2) when being taken out from a reflow oven is restrained is provided.