An ultrasound device includes: an ultrasound generator; an ultrasound probe; and a distal end treatment portion capable of forming a bone hole when pressed against a bone. The distal end treatment portion includes a base portion, and a distal end portion. The distal end portion includes projections and a valley portion between adjacent projections. Each projection is formed of at least one excision surface that is inclined from a base of the projection to a distal top of the projection. The excision surface is capable of finely crushing the bone. The valley portion includes a valley peak at a distal-most meeting point of adjacent projections such that a surface of the valley extending distally from a point at which the valley meets an outer surface of the base portion to the valley peak is inclined.