A cover adapted to an electronic device is provided. An outer side of the electronic device has a connection port. The cover includes a first covering structure and a second covering structure. The first covering structure is disposed on the outer side and has a plurality of first openings. The second covering structure is connected to the first covering structure and has a second opening. The second opening is aligned to the connection port, and the second opening is separated from the first openings. A connector is adapted to be inserted into the connection port through the second opening.