The present disclosure reduces equipment failures, decreases maintenance frequency, and stabilizes cutting operation. Specifically, a holder (5) includes a fitting surface (52) capable of fitting a distal end (2a) of an electrode tip (2). A cutting member (6) having a cutting blade (6b) is attached to the holder (5) and the cutting blade (6b) cuts the distal end (2a) of the electrode tip (2) by rotating the holder (5). On the fitting surface (52), a plurality of grooves (52a) extending arcuately around the rotation axis (C1) as the center thereof are consecutively formed adjacent to each other toward the rotation axis (C1).