The disclosed embodiments relate to a device for operating a tank ventilation system of an internal combustion engine. This device has a fuel tank, an activated carbon filter for collecting and buffering fuel vapors escaping from the fuel tank, a purge air pump and a control unit. The outlet of the purge air pump is connected to the intake tract of the internal combustion engine via a first tank venting valve and connected to the exhaust tract of the internal combustion engine via a second tank venting valve.