A semiconductor module having a compact antenna element capable of providing desired directivity therein has been disclosed. When an electromagnetic-wave radiation window has the capability of a lens, directivity can be set arbitrarily. For improving directivity, a convergent lens for converging millimeter waves or quasi millimeter waves is employed. For impairing directivity, a divergent lens is employed. In the case of the convergent lens, a direction in which radio waves are radiated or received by the antenna element can be set by deviating the center axis of the lens from the center of the antenna element.