To prevent damage to equipment installed on a base or a pedestal by directly releasing a flashover lightning current generated at a protective gap, when the protective gap is installed between contact terminals for releasing out the lightning current to the ground, to the ground without having it pass through the base or the pedestal of a disconnector.

The disconnector 1, provided with a base 3 installed on a pedestal 2, and a contact terminal 11 and a blade 8 fitted on the base 3 through an insulator device 5 and enabling the separating operation of the blade 8 and the contact terminal part 11 by operating the blade by twisting the insulator device by an operating rod 15, has a protective gap formed between itself and the contact terminal 11 in the vicinity of a fixed insulator 6 of the insulator device 7, and an arcing horn 20 connected to a grounding net which is fixed to the base 3 through an insulation member 23.