A cover device of an electronic device is provided. The cover device includes a cover housing configured to cover at least a portion of the electronic device in a first state in which the electronic device is electrically coupled to the cover device, and a bracket including a first surface on which a terminal part is disposed and a second surface which faces the cover housing, wherein the bracket includes at least one first magnet disposed adjacent to the first surface and at least one second magnet disposed adjacent to the second surface, the cover housing includes at least one third magnet, and the at least one third magnet is disposed to align with the at least one second magnet in a second state in which the electronic device is electrically isolated from the cover device.