An air gun for producing nonwoven fabrics has an inlet, a carrier path and a compressed air blow port. The air gun receives filaments spun from high speed spinning nozzles and delivers them onto a screen belt to form a web. The inlet of the air gun receives the filament from the spinning nozzle. The carrier path then puts the filament on an air flow to deliver it while the compressed air blow port is open in the midst of the carrier path to an air inlet from a compressed air source. On a downstream side of the carrier path from the compressed air blow port an exhaust path is provided. When the filament is introduced into the inlet of the air gun, a part of the air flowing into the carrier path is discharged from this exhaust path. Because the exhaust path remains open during filament introduction, a negative pressure at the filament inlet increases thereby sucking the filaments into the inlet. The exhaust path can then be closed and the filaments will be drawn and delivered under constant traction.