Vent valve

The present invention relates to a vent valve (100) with a vent opening (103) for venting a liquid tank in a motor vehicle, with a float (101) in a float chamber (107) for closing the vent opening (103); and multiple guide ribs (109) for guiding the float (101) in the float chamber (107), which are formed by a housing (115) of the float chamber (107) and project into the interior of the float chamber (107).