Abstract: A waterproof cover to be interposed between an inner panel and a door trim of an automobile door is obtained by forming a sheet of a resin composition comprising a linear low-density polyethylene (A) and an ethylene-propylene copolymer (B). Further, a waterproof cover to be interposed between an inner panel and a door trim of an automobile door is obtained by bonding a melt-blown nonwoven fabric made of a polyolefin fiber to an inner surface of a sheet being made mainly of a polyolefin. In manufacturing the waterproof cover, it is preferable that the sheet made mainly of the polyolefin is thermoformed by drape-forming to obtain convex portions. The waterproof cover can suppress occurrence of a vibration sound and is excellent in sound absorption and recycling property.