To provide a polishing device for uniformly polishing a plurality of rotary blades with high accuracy.

This polishing device for a rotary blade includes: a rotary shaft; a plurality of rotary blades held on the same axis of the rotary shaft at fixed spaces in the axial direction; a polishing part including a polishing means coming into contact with the rotary blade to polish the rotary blade and a driving means for driving the polishing means; and a plurality of moving tables for moving the polishing part in the two or more axial direction; and a moving part including a plurality of moving tables for moving the polishing part in the two or more axial directions, wherein a moving table freely moved in the moving direction of a first moving table and energized in the direction of approaching the rotary blade by an elastic body is disposed on a first moving table moved when the polishing part moves, approaches and come into contact with the rotary blade to polish the rotary blade, and the polishing part is disposed on the movable table. When the first moving table moves, the polishing means comes into contact with the rotary blade, and further the first moving table moves, the travel amount reaches a backward travel amount of the movable table. The device includes a measuring means for measuring the backward travel amount.