The disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. Disclosed is a cover device configured to protect an antenna device embedded in an electronic device to radiate a beam of an ultra-high frequency band, the cover device including: a cover frame including a window area corresponding to a radiation area of the antenna device; and a functional structure disposed in the window area on the cover frame and having a stacked structure comprising one or more functional layers.