To provide a tsunami shelter which is of a structure having superior buoyancy action performance, strength and impact resistance for protecting human lives from a heavy tsunami, has an inverting function, and can be placed near ordinary people's residential areas in preparation for a heavy tsunami disaster.

A tsunami shelter body 1 is of a box-like enclosed structure with an improved buoyancy effect. The structure is composed of a composite plate made of a material having a light specific gravity and high strength and impact resistance. To improve the strength, impact resistance performance, and buoyancy action of the composite plate, the interior of the composite plate is constituted of semi-spheric boards. The upper half portion 1d and the lower half portion 1c of the structure are made into ship-bottom shapes, which are the same structures that are vertically and laterally symmetrical, and are welded together along both ends into an integral structure. The upper half portion 1d and the lower half portion 1c of the structure are provided with opening/closing sealing doors 2 and 12 and with opening/closing levers 4, 8 and 9, 10, respectively. Reinforcing beams 7 and 7a and reinforcing pillars 6 and 6a are provided inside the tsunami shelter body 1. Two or more traveling wheels 37 are attached to the outer surface of the bottom of the tsunami shelter body 1. These traveling wheels 37 facilitates the move in a normal circumstance.