An ostomy appliance having a vent covered by a filter. Gas inlet and outlet openings are provided that are in communication with a filter body and arranged so that in use gas flows through the filter body from the inlet opening to the outlet opening. The gas inlet opening communicates with at least two separate and independent closed pathways that have respective inlet openings separated from one another. Each of the pathway outlet openings is covered by a microporous membrane showing improved resistance against blocking of the inlet opening of the filter.