Abstract: An internal combustion engine having an intake air duct with a compressor, a throttle valve, and a crankcase ventilation device with a ventilation duct connected to a crankcase with a crankcase pressure regulating valve, the ventilation duct divided into a first ventilation duct branch connected to the intake air duct upstream from the compressor, and a second ventilation duct branch connected to the intake air duct downstream from the throttle valve. A pressure difference between the pressure in the crankcase or in the ventilation duct upstream from the crankcase pressure regulating valve on the one hand and the pressure in the ventilation duct downstream from the crankcase pressure regulating valve on the other hand is measured by, for example, a sensor, and an evaluation unit evaluates for a correct or incorrect functioning of the crankcase ventilation device and a corresponding item of information can be outputted.