A tip dresser 1 dresses electrode tips 4, 5. The tip dresser 1 is rotated around a rotation axis and includes a holder 2 configured to be rotated around a rotation axis and to have concave tapers 2c, 2d, which make the rotation axis a center, on both faces of the holder 2; and a cutter 3 configured to be fixed to the holder 2 and to be protruded to sides of the electrode tips 4, 5 from the tapers 2c, 2d only at portions of the cutter 3 more inside than outer diameters D1, D2 of the electrode tips 4, 5.