A device for internal centrifugation of mineral fibers including a centrifuge equipped with a peripheral band perforated with orifices distributed in a plurality of annular zones arranged on top of each other, assuming that the centrifuge is in centrifugation position. The device also includes at least two annular zones whose number of orifices per unit of surface area differs by a value greater than or equal to 5%, in particular greater than or equal to 10%, and even 20%.