An ignitor for setting off an incendiary device. The base includes main ribs in the form of grooves that are open towards the outside and extend approximately radially, passing through an annular zone that forms an approximately flat seat by way of which the base can rest in a stable manner on a flat support. The composite filter media structure includes a surface layer deposited on one side of the base substrate where a thermal lamination process can be used to combine the base substrate and the surface layer.