Abstract: The invention relates to a method for producing a cast metal strip using a twin roll casting installation comprising two casting rolls and two lateral plates that together define a molten metal chamber and a casting gap. Molten metal is introduced in to the molten metal chamber and forms the molten metal chamber a molten metal bath with a bath surface that is open to the top. A cast metal strip is conveyed from the molten metal chamber and through the casting gap. A delimiting surface area for collecting particles that are foreign to the molten metal is produced on the surface of the bath under the effect of at least one gas jet. The aim of the invention is to substantially avoid the introduction of particles that are foreign to the molten metal into the surface or into the near-surface zone of the cast strip. For this purpose, the at least one gas jet is directed together with the casting roll onto the bath surface at a distance of the gas jet axis to the contact line of the bath surface.