A ventilation member (100) is provided with a cylindrical part (11), a ventilation filter (19) and a cover part (31). In a mounted state where the cylindrical member (11) is fitted in the cover part (31), spaces functioning as ventilation paths (AR<SUB>2</SUB>, AR<SUB>3</SUB>) are formed between a bottom section (35) of the cover part (31) and the ventilation filter (19) and between a side wall section (39) of the cover part (31) and a body section (17) of the cylindrical part (11). An opening area (S2) of a filter opening section (15) in an in-plane direction (WL) vertical to the thickness direction of the ventilation filter (19) is larger than an opening area (S1) of a connecting opening section (13) in the in-plane direction (WL).
