Provided is a cover accessory for a wireless communication device, includingan electromagnetic suppressing pattern layer on a surface adjoining at least one surface on which an electromagnetic wave is irradiated from the wireless communication device, wherein the electromagnetic suppressing pattern layer includes a first dielectric layer and a frequency selective surface (FSS) pattern with a unit cell having electromagnetic surface resistance periodically repeated thereon, and the FSS pattern is provided by etching the first dielectric layer to inject an FSS pattern material or by printing the FSS pattern material on the first dielectric layer.