The invention relates to a screening, crushing or mixing bucket, which is formed into a bucket of an excavating machine or bucket loader, comprising a bottom plate (1), side walls (2) and at the back of the bucket working drums (3) rotatable about their shafts, which screen, crush or mix the material in the bucket as they rotate and at the same time deliver screened, crushed or mixed material out of the bucket, between or through the working drums (3). In the bucket are casings (4) for the power transmission and bearings of the working drums (3). The casings (4) are limited by frame plates (5) to which the bearing housings (6) of the working drums (3) are attachable. The frame plates (5) have receiving and fastening formings (5a, 5b) for the working drums (3), into which the drums (3) with their bearings (6) can be positioned through the rear side of the bucket. The sides of the casings (4) may in that case be smooth and their opening wall plates are on the rear side of the bucket.