Coffee grinder includes two grinding discs that can be rotated in opposite directions, the axial distance between which defines the degree of grinding of the coffee powder produced. The grinding discs are mounted one over the other within a grinder body, the lower grinding disc being rotatable about a vertical axis of rotation while the upper grinding disc can be adjusted non-rotatably and by an eccentric shaft relative to the lower grinding disc in the direction of the vertical axis of rotation. By rotating the eccentric shaft with a motorized drive, the space between the grinding discs can be changed. This enables almost infinite regulation of the degree of grinding when preparing the coffee.