PROBLEM TO BE SOLVED: To solve the problem that there is no system capable of utilizing a product although it is proved that air ions, ozone, shock waves, ultraviolet rays, etc. which are products generated by electric discharge as well as by an electric shock are effective in growth promotion of general plants including farm products when applied with moderate intensity and amount in latest studies.SOLUTION: A discharge side electrode 9 to which the output end of a high voltage generating part is connected, and an earth side electrode 13 facing the discharge side electrode through a discharge gap G, are surrounded by a guide member 3, and the product generated by electric discharge is released to the outside only from an opening 5.
