To provide an automobile body cover device capable of easily covering the automobile and being accommodated in a trunk without damaging and remodeling a car body.

The automobile body cover device is provided with a device body constituted to unwind/wind the body cover; and a stand part mounted with the device body through a link mechanism. An elastic support member is projectably provided on the stand part and the device body can be accommodated in the trunk room in the state that it is stretched/supported between inner walls of the trunk room by the elastic support member. The device body is movably mounted to the stand part from an upper position, i.e., a usage position to a lower position, i.e., a non-usage position. A plurality of core materials are arranged on the cover body of the body cover at a position perpendicular to the unwinding/winding direction of the body cover in parallel at a constant gap.