A machine (1) is serving the purpose of comminution for example domestic garbage, refrigerators, tires, furniture, carpets, mattresses, stubs, demolition timber and similar materials. The machine has a funnel (2) for accommodating the waste, a cutting table (4) placed at the bottom of the funnel with at least one set of fixed, parallel lower knives (9a, b) which mutually are separated by openings (10a, b) through the table, at least one rotatable axle (5a, b) of a drive unit (7) which axle is placed above the cutting table into a direction, which extends perpendicular to the lower knives, and a number of disc-shaped upper knives (8a, b) fixed to the axle, each of which knives is provided with a number of teeth (13a, b) and partly extends down into each their opening of the table. The lower knives are running into a direction, which intersects the axis (18) of the axle or an area around this. Thereby it is obtained that the teeth of the upper knives will have angle of action of about 90°, and the stress of forces, which they exercise, will have no substantial components into the radial direction of the upper knives and along the lower knives. The advantage of this construction is that the machine is able to securely, in a fast way and efficiently carry out a process of comminution by optimum utilizing the supplied energy, and with the given dimensions the machine has furthermore a larger capacity than known hitherto.