The invention relates to a method for triggering a gas insulated switching spark gap and to the spark gap itself. Triggering requires only a small amount of energy using a coherently or incoherently scattering, triggering light source illuminating the gap between the electrodes. The triggering light source releases electrons from the metal particles present in the insulating gas of the switching spark gap. Said electrons are used as starting electrons to form sparking conduits. The metal aerosol is produced in a spark gap, an aerosol generator, with electrodes made from said metal aerosol material. One of the constituents of the insulating gas flows through the aerosol generator. The insulating gas in the switching spark gap consists of at least one constituent.