A wireless IC device includes a base material sheet having a long-side direction and a short-side direction, an antenna element provided on a surface of the base material sheet and that includes two radiation portions extending in the long side direction with a predetermined gap therebetween and two connection portions located in a gap through which the two radiation portions oppose each other, a wireless IC element connected to the two connection portions via a conductive bonding material, and a resist layer that covers the two radiation portions and does not cover the two connection portions and at least areas adjacent to the connection portions in the short-side direction.