An apparatus for pulverizing a material, the apparatus comprising: - a stationary housing having an interior space and at least one interior wall facing the interior space, - a plurality of sawblades put together to form a cutting unity disposed in the interior space and arranged rotatable with respect to the stationary housing in a rotational direction, wherein the sawblades are disc-shaped and have a periphery provided with a plurality of cutting teeth for cutting the material and a plurality of collecting notches disposed in front of the cutting teeth with respect to the rotational direction for collecting the cut material, - an inlet opening for feeding material to be pulverized to the interior space, and - an outlet opening for dispatching the pulverized material from the interior space, wherein the interior wall is provided with a plurality of recesses facing the periphery of the sawblades, arranged to receive the cut material from the collecting notches of the sawblades, and to revert the cut material to the peripheries of the sawblades so that the material will be cut multiple times before it is dispatched from the apparatus, characterized in that the peripheries of the sawblades are provided with a plurality of empty notches without any cutting teeth arranged between the collecting notches, the sawblades are rotated in relation to each other so that a front part of the empty notches of the sawblades are aligned with the collecting notches of the neighbouring sawblades and so that the empty notches and the collecting notches together form a slot in an axial direction for collection of the cut material, the empty notches are longer than the collecting notches along the periphery of the sawblades so that grooves (37a-b) are formed between the sawblades and between the cutting teeth, the cutting teeth and the grooves (37a-b) form a plurality of groups along the periphery of the cutting unit, wherein the cutting teeth within the same group are aligned in the axial direction, and two neighbouring groups have the cutting teeth and grooves (37a-b) arranged so that each groove (37a-b) of a first group is followed by a cutting tooth in the next group along the periphery of the sawblade, wherein the cutting teeth in two neighbouring groups cooperate to cut the material along the width of the material. - a stationary housing having an interior space and at least one interior wall facing the interior space, - a plurality of sawblades put together to form a cutting unity disposed in the interior space and arranged rotatable with respect to the stationary housing in a rotational direction, wherein the sawblades are disc-shaped and have a periphery provided with a plurality of cutting teeth for cutting the material and a plurality of collecting notches disposed in front of the cutting teeth with respect to the rotational direction for collecting the cut material, - an inlet opening for feeding material to be pulverized to the interior space, and - an outlet opening for dispatching the pulverized material from the interior space, wherein the interior wall is provided with a plurality of recesses facing the periphery of the sawblades, arranged to receive the cut material from the collecting notches of the sawblades, and to revert the cut material to the peripheries of the sawblades so that the material will be cut multiple times before it is dispatched from the apparatus, characterized in that the peripheries of the sawblades are provided with a plurality of empty notches without any cutting teeth arranged between the collecting notches, the sawblades are rotated in relation to each other so that a front part of the empty notches of the sawblades are aligned with the collecting notches of the neighbouring sawblades and so that the empty notches and the collecting notches together form a slot in an axial direction for collection of the cut material, the empty notches are longer than the collecting notches along the periphery of the sawblades so that grooves (37a-b) are formed between the sawblades and between the cutting teeth, the cutting teeth and the grooves (37a-b) form a plurality of groups along the periphery of the cutting unit, wherein the cutting teeth within the same group are aligned in the axial direction, and two neighbouring groups have the cutting teeth and grooves (37a-b) arranged so that each groove (37a-b) of a first group is followed by a cutting tooth in the next group along the periphery of the sawblade, wherein the cutting teeth in two neighbouring groups cooperate to cut the material along the width of the material.