Abstract: Provided is an air dryer that includes a compressor, an air drying chamber, a vortex tube, and an external discharge member. The air drying chamber rotates compressed air supplied from the compressor to remove moisture from the compressed air using Coanda effect and dry the compressed air, and simultaneously to accelerate and discharge the compressed air. The vortex tube divides the dried and compressed air, discharged from the air drying chamber, into cool air and hot air, and discharges the cool air and the hot air. The external discharge member collects the dried hot air and the dried cool air, discharged from the vortex tube, and discharges the dried hot air and the dried cool air at a constant pressure to the outside.