A method for feeding and conveying material in a pneumatic material conveying system, such as a waste conveying system, which conveying system comprises at least two feed points of material, particularly of waste material, a material conveying pipe connected to the feed point by means of at least one branch conveying pipe (101, 102) connected to at least one feed pipe (103, 104), a separator device in which the material being conveyed is separated from conveying air, conveying air channels (105,106), and means (3, 4) for providing a pressure difference in the conveying pipe at least during the conveyance of the material, wherein conveying air is circulated in a circuit which is formed by at least a part of the conveying pipe and the conveying air channels (105, 106) in to which circuit the suction side of at least one vacuum generator is connected and in which the suction side of at least one blower device is connected to the conveying air channel (105, 106) coming from the separator device of the circuit and the blowing side to the conveying pipe or a section of the circuit in connection with the conveying pipe so that it is possible to circulate air with the blower device in said circuit, providing underpressure in the conveying pipe at least at the point of the feed point intended to be emptied, arranging underpressure provided by the devices (3, 4) for generating underpressure of the circuit activated in the system i.e. suction in the material conveying pipe (100, 100A, 100B, 100C, 100D, 100E, 100F, 100G, 100H, 1001) greater than a pressure effect i.e. blowing provided by the at least one blower device, emptying the feed points in the conveying pipe using an emptying sequence in which first is emptied a feed point located closer the separator device in the material conveying direction and next a feed point located farther from the separator device in the material conveying direction, and emptying the feed points in the conveying pipe using said emptying sequence in which: - opening a connection from the feed point to the conveying pipe so that material conveys from the feed point to the conveying pipe, - repeating the following steps until all desired feed points have been emptied ∘ opening a connection at least from one next feed point to the conveying pipe, ∘ closing a connection from the previous feed point to the conveying pipe, closing the connection of the last feed point to be emptied to the conveying pipe, and - providing a blowing effect in the conveying pipe, whereby the blowing effect together with the suction effect convey the material in the conveying pipe to the separator device. - opening a connection from the feed point to the conveying pipe so that material conveys from the feed point to the conveying pipe, - repeating the following steps until all desired feed points have been emptied ∘ opening a connection at least from one next feed point to the conveying pipe, ∘ closing a connection from the previous feed point to the conveying pipe, ∘ opening a connection at least from one next feed point to the conveying pipe, ∘ closing a connection from the previous feed point to the conveying pipe, - providing a blowing effect in the conveying pipe, whereby the blowing effect together with the suction effect convey the material in the conveying pipe to the separator device.