A wireless communication device includes a wireless IC device, a dielectric substrate, and a metal plate. A radiation conductor coupled to the wireless IC device is provided on the front surface of the dielectric substrate, and a ground conductor connected to the radiation conductor through an interlayer connection conductor is provided on a back surface. The dielectric substrate is fixed to the metal plate via an insulating adhesive, and is crimped by a conductive member. The front and back surfaces of the metal plate are electrically connected to each other by the conductive member, and when a high-frequency signal is supplied from the wireless IC device, a high-frequency signal current on the front surface side of the metal plate is conducted to the back surface side of the metal plate through a surface boundary portion between the conductive member and the metal plate, and radiated as a high-frequency signal.