Provided is a dental ultrasonic cleaning device that efficiently cleans teeth or dentures in an oral cavity using ultrasonic waves. A dental ultrasonic cleaning device 1 emits ultrasonic waves through a cleaning-liquid (W1) to the surface of a cleaning-target 26, ultrasonically cleaning it. An ultrasonic horn 24 propagates ultrasonic waves being generated by an ultrasonic-wave transducer 23 and emits them from the vibratory surface 25 provided at the tip-end of the horn 24. A liquid-reserving part 27 is provided, surrounding the vibratory surface 25 of the ultrasonic horn 24, which temporarily reserves the cleaning-liquid (W1) between the vibratory surface 25 and the cleaning-target 26. A cap-member 33 is provided at a certain interval opposite the liquid-reserving part 27. A cleaning-liquid discharge-tube inlet 35 is connected to a vacuum tube 36 within the cap-member 33, allowing the cleaning-liquid W1 used during the ultrasonic cleaning to be vacuumed from the oral cavity, into the cap-member 33, and then discharged through the vacuum tube 36.