A device (30) for applying adhesive is used in fiber web machine slitter-winder. The slitter-winder has an unwinder for a machine roll, slitter blades for slitting the unwound web into partial webs, and a winder forming them into rolls. The device (30) applies adhesive on ends of partial webs attaching the ends of the partial webs onto the web rolls. The device (30) has a support structure (31), a moving element (32) on the support structure and two adhesive nozzles (33, 34) on the moving element. The adhesive nozzles (33, 34) are attached to the moving element (32) such that the nozzles (33, 34) are spaced apart in the direction of travel of the moving element (32) so that a trailing nozzle can be accelerated to operating speed before traversing the partial webs, and a leading nozzle can extend further in the direction of travel than the moving element.