Prechamber spark plug

The plug has an insulator (5) arranged in a housing (1), and a central electrode (6) surrounded by the insulator. The central electrode supports an ignition electrode arranged in a pre-chamber (3) and includes multiple electrode arms (7). Each arm has a rear section (7a) extending transverse to a longitudinal direction of the central electrode, and a front section (7b) running along a pre-chamber wall (3a). The arms are embedded into the central electrode and projected from a side surface of the central electrode. The ignition electrode is formed as a bend part made of sheet metal. An independent claim is also included for a method for fastening an ignition electrode.