The present invention relates to a turbo air blower having waterproof and damp-proof functions. The turbo air blower has a waterproof structure so as to be installed outdoor, thereby obviating the need to add a pressure-feeding line and manufacture an air blower room which are required for conventional indoor installation. Further, the turbo air blower has a reliable damp-proof function by installing various dehumidifying parts therein, thereby being capable of preventing a device from being corroded by humidity and dampness as well as providing dehumidified pressure-fed air.