To provide an inexpensive device for disaster prevention, which effectively functions with a simple constitution.

Shielding plates are placed in a fixed fashion on both ends side of a bed in the longitudinal direction. At these shielding plates, a pair of bed bodies 1 are provided opposing right and left via a pair of right and left rotation centers. Both bed bodies 1 can convert the posture in the state where the upper face is horizontal and in the state where it is upright facing outward. Each bed body 1 has a partly circular shape in a part of the side opposing when it is in the horizontal state, and has weights so that they go down when the posture is converted from the horizontal state into the upright state. Both weights are connected with a detachable locking link 61 when coming back to the upright position. At the shielding plate 58, a stopper 60 is provided for stopping the bed bodies 1 in the upright state, and for forming a safety space between both bed bodies 1 in the upright state.