To provide a treatment instrument that allows a probe placed in a probe holding part to be gripped easily, and allows the probe to be placed in the probe holding part in a stable manner.SOLUTION: A treatment instrument 1 includes a gripping part that an operator grips, a probe 3 having a head part, and a probe holding part for detachably holding the probe 3. The probe holding part includes a recessed part 6 into which the head part is inserted. In a state in which the probe 3 is placed in the probe holding part, a space into which fingers of the operator can be inserted is formed between the gripping part and the probe holding part. First means (slit) is formed in the head part, and when the head part is inserted into the recessed part 6, second means (protrusion) that engages with the first means is formed in the recessed part 6.SELECTED DRAWING: Figure 1【課題】プローブ保持部に載置された状態のプローブが掴みやすく、且つ、プローブをプローブ保持部に安定して載置可能な治療器を提供する。【解決手段】治療器１は、操作者が握る把持部、及び、ヘッド部を有するプローブ３と、プローブ３を着脱可能に保持するプローブ保持部とを備えている。プローブ保持部はヘッド部が挿入される凹部６を有し、プローブ保持部にプローブ３を載置した状態において、把持部とプローブ保持部との間に操作者の手指が挿入可能な空間が形成され、ヘッド部に第１手段（スリット）が形成され、ヘッド部が凹部６に挿入されたとき、第１手段と嵌合する第２手段（突起）が凹部６に形成されている。【選択図】図１
