Abstract: A functional substance adsorption device for fibers including: a casing having a space formed therein and an opening and closing door located on the front surface thereof; a drum rotatably disposed inside the casing and having a space formed therein to put the fibers therein and a plurality of fine through holes formed thereon; a driving part disposed on one side of the casing to rotate the drum; and a fine particle supply part comprising a fine particle supply hose communicating with the outer periphery of the casing, a vaporization tank connected to one side of the fine particle supply hose, a pneumatic ultrasound generator disposed inside the vaporization tank to vaporize an antimicrobial agent, and an air compressor for supplying pneumatic pressure to the pneumatic ultrasound generator.