Many crawler vehicles for rescue use have been researched so far. In the near future, if this type of research is to advance to the next stage, experiments in realistic environments are necessary. Particularly, dustproof and waterproof capabilities are necessary to operate in a real environment. The existing sealing technology for the driving parts is difficult to be used for robots whose outputs are small because the friction loss is not small. This paper describes proposal of the high strength retractable skin and development of the closed type crawler vehicle covered by it.