An ultrasound instrument (11) comprising: a vibration generating part (16) which has a first screw part (24) and generates ultrasonic vibrations and a probe (14), further comprising a probe main body (27) which extends along a longitudinal axis (C) and to which the ultrasonic vibrations generated by the vibration generating part (16) are transmitted, a second screw part (31) which is disposed on the probe main body (27) so as to face the first screw part (24) and which has a screw thread in the opposite direction from the first screw part (24), and an instrument part (28) which is disposed on the leading end part of the probe main body (27). The ultrasound instrument (11) further comprises a coupling part (17), further comprising: a first engagement part (32) which engages with the first screw part (24) and a second engagement part (33) which engages with the second screw part (31). The coupling part (17) couples the vibration generating part (16) and the probe part (14) together, such that the ultrasonic vibrations can be transmitted to the probe (14) side, by being rotated in a first direction about the longitudinal axis (C) relative to the vibration generating part (16) and the instrument part (28), and can separate the vibration generating part (16) and the probe (14) from each other by being rotated in a second direction opposite to the first direction.La présente invention concerne un instrument à ultrasons (11) comprenant : une partie produisant des vibrations (16) qui possède une première partie (24) de vis et produit des vibrations ultrasonores et une sonde (14), comprenant en outre un corps principal (27) de sonde qui sétend le long dun axe longitudinal (C) et vers laquelle sont émises les vibrations ultrasonores produites par la partie produisant des vibrations (16), une seconde partie (31) de vis qui est disposée sur le corps principal (27) de sonde de manière à faire face à la première partie (24) de vis et qui possède un filetage de vis dans le sens o
