To provide a structure for an underground shelter in which even a number of the weak in a disaster can easily and speedily evacuate, which can be constructed inexpensively without requiring excessive costs, and of which a safe evacuation condition can be maintained without inviting an unexpected state such as floating ot falling even under an attack of big tsunami.

A structure for an underground shelter comprises: a shelter body portion in which an evacuation chamber is formed and which is buried while settling at least a part of a lower side under the ground. The outside and the evacuation chamber are communicated by evacuation gude means including opening/closing means which can be shut off in an evacuation route.