In various fields, in which motor-driven chain saws are used, it is necessary that operators while moving about are protected from injuries caused by the saw chain when the chain saw is not being used. A chain guard to cover the saw chain while the machine is not in use is already known from U.S. Pat. No. 3,344,818. Especially while handling top-handle saws, which are used while moving in tree tops and while climbing ropes, it is important that the operator does not come into contact with the sharp cutting elements of the saw chain and sustain injury.