PURPOSE: To use a simplified rest room by way of lifting it up at the time of an event, etc., when a crowd of people gather and at the time of emergency of a large earthquake, etc., by previously burying it at a square and in a park planned as an event place where the crowd of people gather and a place of refuge at the time of a disaster of the large earthquake, etc.

CONSTITUTION: This device is used when city functions are paralyzed and when a crowd of people are short of places to gather and urinate. A unit is made by burying an external housing 2 mainly made of fiber reinforced plastic underground and building an internal housing 1 made of a single or a plural number of fiber reinforced plastic plates connected to each other as a main material in the inside of the external housing 2. The internal housing 1 is devised free to slide vertically, and a fixture 10 installed inside above the external housing 2 or a closing cover 8 of the unit is made as an engagement part of the internal housing 1 at the time when the internal housing 1 appears on the ground surface.