ANTENNA DEVICE

Each of first, second, and third stacked parts includes a resin member a conductive film that covers the resin member. The first, second, and third stacked parts are stacked one another. The first stacked part has an external port to propagate radio waves to an external device. The second stacked part has an intermediate passage to propagate the radio waves therethrough. The third stacked part has antenna radiating elements to propagate the radio waves to an external space. The first stacked part and the second stacked part are stacked to form a waveguide that is extended. The waveguide is connected to the external port of the first stacked part and to one end of the intermediate passage to propagate the radio waves therethrough. The antenna radiating elements are coupled to the one end of the intermediate passage.