To provide a simple and inexpensive tsunami shelter which is capable of performing rapid and easy evacuation, and surely ensuring the air required for breathing until tsunami is ended.

A tsunami shelter comprises an airtight wall 1 which is fixed to the ground and surround the prescribed space, an opening part 2 which a person can enter/go out of the space surrounded by the airtight wall, is provided in the airtight wall. An air chamber capable of keeping the air even when water by tsunami enters inside is provided in the space. The air chamber is formed so that the air of the necessary volume for the prescribed number of persons evacuating inside can breathe for several minutes even when water enters by tsunami. The air of the required volume until tsunami is ended can surely be ensured in the shelter.