A protecting cover detachably disposed at an electronic device is provided. The electronic device has an arc side and a first magnetic element disposed in the arc side. The protecting cover includes a covering part and a pivot part. The pivot part is connected to the covering part, and the pivot part includes an arc area and a second magnetic element disposed in the arc area. The outer line of the arc area corresponds to the arc side, and the first magnetic element is magnetically attracted with the second magnetic element to make the pivot part detachably connected to the arc side. The protecting cover uses the second magnetic element in the pivot part to attract the electronic device with the first magnetic element in the arc side, and thus the protecting cover can be fixed at the electronic device.