PROBLEM TO BE SOLVED: To enhance safety by elongating the creepage distance between a needle electrode and an opposed electrode to perform discharge over a wide range.SOLUTION: This active seed generator includes a body case 4, the needle electrode 12 arranged so as to leave a predetermined distance from the insulating substrate 7 provided in the body case 4, the opposed electrode 13 being in contact with the insulating substrate 7 and a power supply 14 for applying voltage across the needle electrode 12 and the opposed electrode 13. An adsorbing means, which covers the surface of the insulating substrate and adsorbs the moisture in the vicinity of the insulating substrate, is provided and the opposed electrode 13 is provided in contact with the adsorbing means.
