PURPOSE: To provide a method and device for separating dust and impurities that are attached to a web, and capable of preventing diffusion.

CONSTITUTION: In a paper machine or in a finishing device of the same, in particular in a slitter-winder, the method concerns a method for collecting and removing dust D, and the like that is separated from a web W, the dust, and the like, are sucked off from the web before and after a high-pressure blowing P1. In the paper machine or in a finishing device of the same, in particular in a slitter-winder, in the device for collecting and removing dust D, and the like, that are separated from the web W, the device 10 comprises a pressurized chamber space 11, in which a nozzle opening 12 for application of a blowing P1 to the web W and suction openings 13, 23 for removing the dust present in connection with the web W are provided. The air chamber 11 in the device 10 is pressurized so that the high-pressure blowing P1 is blown through the nozzle opening 12 of the air chamber 11 towards the web W, and that the suction openings 13, 23 of the device 10 are placed before and after the nozzle opening 12 in the running direction S of the web W.