Air dryer and compressed air drying method using same

The present invention relates to an air dryer and a compressed air drying method using the same, the air dryer comprising a dehumidification box including a pair of main air dryers, a main compressor, a first direction change valve part, a regeneration-dedicated dryer, a second direction change valve part, a heating part, a cooler, and a regeneration-dedicated compressor. According to the air dryer of the present invention, the supply of high-temperature dry air required for regeneration is received from a separate regeneration-dedicated air dryer, thereby regenerating a dehumidifying agent, and dehumidifying by mixing the dehumidifying agent with wet air of a wet air introduction line of the air dryer, thereby continuously supplying a certain amount of dry air. Consequently, compressed dry air can be continuously supplied without loss to an automated facility requiring dry air, a semiconductor manufacturing line, a coating line, a chemical process that causes a chemical reaction when contacting with water, a