PROBLEM TO BE SOLVED: To provide an interdental cleaning instrument capable of enhancing an insertion property of a cleaning part in between molars.SOLUTION: An interdental cleaning instrument comprises a base part (10) and a cleaning part (20). The base part (10) has a shaft section (12) and a gripping section (14). The cleaning part (20) includes an insertion end section (12a), and is shaped to cover a section of the shaft section (12) having a dimension equal to or less than the axial dimension thereof. At least the shape of the base part (10) is set such that: while a section separated by 10 mm from the tip of the cleaning part is immobilized, a first pressing force is 0.3-1.4 N inclusive, which is required in pressing by 10 mm a section separated by 2.5 mm from the tip of the cleaning part； and while a section separated by 35 mm from the tip of the cleaning part is immobilized, a second pressing force is 0.5-2.5 N inclusive, which is required in pressing by 10 mm a section separated by 8.0 mm from the tip of the cleaning part.SELECTED DRAWING: Figure 1
