Abstract: A wet grinding device having a container for receiving therein products to be ground as well as grinding balls, the container being equipped with a mixer, a delivery device for feeding the products to be ground into the container, a discharge outlet for the broken-up products, as well as a drive device for the mixer. The wet grinding device is characterized by an operating chamber divided into a plurality of grinding zones of increasing volume, the operating chamber including a mixer shaft therethrough, the latter being rotatably horizontally supported by the container. The shaft is provided with blades which have a diameter which is proportional to the diameter of the respective grinding zones.