Problem: To provide a slot nozzle assembly that can extrude a fluid material essentially uniformly in the longitudinal direction of the slot.Means of Solution: A slot nozzle assembly (1) for extruding a fluid material, that has a slot (9) for extruding a fluid material, a plurality of material exit ports 5b), and a plurality of material dispersion passages (7) communicating with the slot (9) and the plurality of material exit ports (5b) respectively; the widths of the plurality of material dispersion passages (7) in the longitudinal direction of the slot (9) widen from the plurality of material exit ports (5b) toward the slot (9).