A twin roll caster for an apparatus for confining the impurities in a molten metal fed by means of a discharger and contained into an area of a strip continuous casting mold delimited by the side surfaces of two casting rolls with counter-rotating horizontal axis and by two containment side plates positioned in contact with the rolls' bases is provided. The apparatus includes a discharger having at least two first series of holes for the molten metal supply, each series being formed by at least a pair of holes respectively directed towards one of the opposed side surfaces of the two rolls and at least a second pair of holes for the molten metal supply, each hole of such second pair being directed towards the side plate nearest thereto, and said at least one second pair of holes being positioned at a greater depth with respect to said two first series of holes, and at least two pairs of barriers present in one part of the area comprised between the end of the nozzle and the containment side plates, forming the cross-sections of said barriers therebetween, lying on a same horizontal plane, an Y angle.