Abstract: The invention relates to an arrangement of nozzles with negative pressure intended for the treatment of webs. A nozzle directs a drying and supporting gas flow at the web and which has a box construction, and a nozzle space formed at one side of the nozzle. The nozzle space is provided with a nozzle slot defined by nozzle walls. One of the walls operates as a curved guide face which is fitted to turn the gas flow passed out of the nozzle slot, based on the Coanda effect, so as to make it parallel to the carrier face formed on the top face of the nozzle. At least one second nozzle slot is provided at a distance before said first nozzle slot, in the running direction of the web. A flow guiding fitted in connection with the second nozzle slot is arranged so that the flow has a substantially large velocity component perpendicular to the direction of running of the web. The velocity component parallel to the plane of running of the web of the flow passed out of the second nozzle slot is larger than zero.