It is stated in this paper that how behaves the discharger when it used as a lightning arrester and that the arrester, having series gap as in modern pratice, is undesirable. Next stated that though it is impossible to design a truly ideal arrester by the principle of a discharger, but it is possible to design a truly ideal lightning arrester by the combination of the principles of an ideal discharger and of an ideal high frequency energy absorber. At the end, it is explained the principle of a high frequency energy absorber which is designed by the author.