A stationary blade of a gas turbine, having a simple structure in which sufficient cooling is achieved and the drop in pressure of cooling vapor is decreased so that the turbine efficiency is prevented from lowering. The shape of a vapor passage is simplified to prevent the drop in pressure because an outer shroud (3) of the stationary blade and a blade unit (2) are cooled with vapor, while an inner shroud (4) is cooled with the air supplied from another system.