A protective cover applying to cover or support a tablet computer is provided. The protective cover has a first covering part, a second covering part, a third covering part, a first magnetic element, a second magnetic element, and a third magnetic element. The first covering part has a first connecting lateral, a second connecting lateral and a plurality of first hard domains, and adjacent first hard domains are connected to each other flexibly. The second covering part is connected to the first connecting lateral flexibly and has a plurality of second hard domains, and adjacent second hard domains are connected to each other flexibly. The third covering part is connected to the second connecting lateral flexibly. The first magnetic element is disposed at the first covering part. The second magnetic element is disposed at the second covering part. The third magnetic element is disposed at the third covering part.