To retard the generation of overvoltage in a mesh, and prevent apply of overvoltage to equipment and facilities in the premises of a substation from the mesh by arranging an arrester for absorbing the energy of an inductive lightning stroke between an overhead earth-wire and the mesh.

An overhead earth-wire 5 drawn down from a dead-end tower 3 is connected to a mesh 6 for earth through an arrester 7. By arranging the arrester 7 having high energy-absorbing capability, inductive lightening stroke advancing from the overhead earth-wire 5 is absorbed with the arrester 7. The generation of overvoltage in the mesh in the premises of a substation is retarded, and the mesh 6 is kept in zero potential. By retarding the generation of overvoltage in the mesh 6, trouble or malfunction of equipment and facilities in the premises of the substation caused by overvoltage from the mesh can be prevented.