A web cam is provided, comprising: a body, having a receiving space for receiving a lens, and two supporting arms extending from the periphery of the body; a shell from which a pivot connecting part is extended; and a connecting element, passing through the holes of the supporting arms of the body and the holes of the pivot connecting part of the shell, such that the shell is rotatable with respect to the body, thereby the shell can cover or move away from one side of the body having the lens.