In a venting system, in particular for a fuel tank of a motor vehicle, which has a sorption filter for temporarily storing fuel evaporating from the fuel tank and a fluid-conveying conveying device situated between the sorption filter and an air supply or an intake manifold of an internal combustion engine, according to the present system, the conveying device is a bidirectional conveying device which is switchable in a first conveying direction in the direction of the internal combustion engine for regenerating the sorption filter and in a second conveying direction in the direction of the sorption filter for carrying out a fuel tank leak diagnosis.