A mixing device, in particular bulk material mixing device, with at least one mixing container comprises a receiving region for receiving a material to be mixed, with at least one mixing unit which is configured for mixing the material to be mixed that is present in the mixing container, and with at least one lump breaker unit comprising at least one cutter element which protrudes into the mixing container, wherein the at least one lump breaker unit is arranged in a frontal region of the mixing container.