To simplify the attachment of a cover member, an air intake duct 10 includes a duct body 12 having an air flow passage 14 communicating from an inlet port 12a to an outlet port 12b and a vent hole 28 communicating from the air flow passage 14 to the outside, an air permeable cover member 32, and a holding member 34 secured to extend along an outer inner circumferential surface or an inner circumferential surface of the duct body 12 and to hold a portion of the cover member 32 covering the vent hole at a location different from the vent hole 28. The holding member 34 is detachably attached to the duct body 12.