Abstract: A lifesaving device is formed of a plurality of gas charge devices, a plurality of cylindrical bodies each of which has one end connected to one of said gas charge devices corresponding thereto and the other end which is closed, each of said cylindrical body having an outer configuration of generally flat plate in deflated condition, and a cylindrical body holding member for holding said cylindrical bodies in the deflated condition to be folded therein or wound-up thereon, wherein said cylindrical bodies are inflated and deployed simultaneously in response to operation of the respective gas charge devices to the extent that a predetermined buoyancy force is obtained.