Oil mist separator of an internal combustion engine

The invention relates to an oil mist separator of an internal combustion engine, comprising at least one gas-permeable diffusion separation body, through which a crankcase ventilation gas of the internal combustion engine can flow and in which oil mist present in the crankcase ventilation gas can be separated from the gas. The novel oil mist separator is characterized in that in the or each diffusion separation body additionally continuous free gas channels are formed, and that, viewed in the flow direction of the crankcase ventilation gas, behind the gas channels at least one further diffusion separation body, or an impingement separation surface is disposed at a distance from the or each diffusion separation body.