A guiding device can include a guide including a through hole for insertion of an ultrasound probe that forms a tunnel to a bone. The guide can be configured to guide movement of the ultrasound probe inserted through the through hole; an offset portion offset from an axis of the through hole. The guiding device can also include an offset portion with an abutment portion configured to abut to an outer wall of the bone, on a side on which the through hole is located, in a direction orthogonal to the axis and a bone-tunnel introduction portion provided on an opposite side to the side on which the through hole is located and being configured to be inserted into the tunnel. The bone-tunnel introduction portion can have a sectional polygon shape smaller than a polygon on an inner circumferential face of the through hole.