Method for feeding in and for handling waste material in the channel section of a pneumatic wastes conveying system, in which method waste material or recycleable material is fed into a feed-in container from the input aperture of an input point of a pneumatic pipe transport system for material and onwards into the channel section between the feed-in container and the material conveying pipe, from where the material is conveyed along with the transporting air via the material conveying pipe to the delivery end of the pneumatic material conveying system, where the material is separated from the transporting air. In the method the material is acted upon by the combined effect of suction and replacement air in the channel section by bringing about compression in size in at least a part of the material being conveyed, by means of an impediment arranged between the conveying pipe and the material to be handled, or against the impediment, before transportation of the material to the delivery end of the pneumatic transport system for wastes.