Ventilation member and vented housing using the same

A ventilation member (1) having: a breathable film (4) transmitting gas passing through an opening portion (8) of a housing (7) in a state in which the breathable film (4) is fixed to the opening portion (8); and a support (2) including a supporting portion (2a) for supporting the breathable film (4) and an insertion portion (2b) to be inserted into the opening portion (8) of the housing (7); wherein a lock structure for locking the support (2) in the housing (7) by rotating the support (2) around a central axis of the support (2) is formed in the insertion portion (2b).