In an ultrasonic hair treatment device comprising a vibrator having a vibration element for generating ultrasonic vibrations and a receiver facing the vibrator as to apply the ultrasonic vibrations to a bundle of hairs which is pinched between the vibrator and the receiver, the vibration element has an oblong plate shape so as to have a plurality of resonance points arranged like a periodic lattice on a vibration face disposed in a thickness direction thereof, a plurality of circular recesses or grooves for trapping a hair treatment agent therein is formed on a vibration face of a head of the vibrator facing the receiver corresponding to the resonance points of the vibration element.