It is an object of the invention to provide semiconductor devices which can protect privacy of consumers or holders of commercial products and control the communication range according to use, even when the semiconductor device which can exchange data without contact is mounted on the commercial products. A semiconductor device of the invention includes an element group including a plurality of transistors over a substrate; a first conductive film functioning as an antenna over the element group; a second conductive film surrounding the first conductive film; an insulating film covering the first and second end portions; and a third conductive film over the insulating film. The first conductive film is provided in the shape of a coil, and each end portion of the first conductive film is connected to the element group. First and second end portions of the second conductive film are not connected to each other.