A device for securing a living body by pressing includes a living body pressing air bag, a curled elastic member of an approximately cylindrical shape, disposed on the outside of the living body pressing air bag and changeable in size in a radial direction, and a curled elastic member pressing air bag, disposed on the outside of the curled elastic member and inflated to press an outer peripheral surface of the curled elastic member inward to reduce a diameter of the curled elastic member, to thereby press the living body pressing air bag against the living body via the curled elastic member. This can provide a living body pressing and securing device provided with a novel automatic cuff winding mechanism that can simplify and downsize the winding mechanism, hardly causes skin tension on the body surface, and ensures uniform winding strength over the entire surface of the pressed site.