Up to now, The communications space of WSCS (Waseda Shadow Communication System) is received limitation by projection screen, and this limitation becomes a problem when it tries to express the different space. Against this problem, we developed smoke screen to enhance extensity. This device prevents smoke from diffusing by confining smoke in the layer of air, and it can project the image with stability. As a result, the prospect was obtained in the following two points. First, this device is effective to strengthening appearance of solidity of the shadow image. Second, it is effective to enhance extensity of WSCS.