Abstract: Disclosed is an air permeable cap, which includes a body connected to an opening of a lamp housing for a vehicle, the body having an inner space formed therein to communicate with the lamp housing and having an air permeating hole formed at one end thereof to communicate with the inner space; a cover member having an insert space formed therein so that one end of the body is inserted therein; and a plurality of support protrusions configured to protrude from an inner side of the cover member toward a center of the insert space to support the body to be spaced from the inner side of the cover member so that an air permeating channel for allowing air flow is formed between the inner side of the cover member and the body.