An insulating piece for an electronic device is provided. The electronic device includes a first housing component and a second housing component. The first housing component includes at least one hook portion connected to the second housing component. The insulating piece includes a first covering portion, a second covering portion and at least one concave structure. The first and second covering portions extend in different directions. The concave structure is connected between the first and second covering portions. The concave structure and the second housing component form an accommodating space therebetween to accommodate the hook portion. The first and second covering portions cover inner sides of the first and second housing components respectively.