PURPOSE: To obtain the titled electrode disk which extended a life, and for which a conventional frequent replacement work is not required, by specifying a position relation of each of plural adjacent holes which is formed in a shape of a concentric circle and also in the diameter direction in the inside of plural grooves of the outside peripheral part.

CONSTITUTION: When cutting of a steel material to be cut 102 is repeated by said electrode disk 103, the disk 103 itself is melted and consumed by an arc head, and its diameter becomes small gradually. At the same time, a working groove 106 is also consumed, and a molten metal removing function is lowered and also lost. However, at the same time, the outermost peripheral part of an oblong hole 111 is melted, and functions as a working tool instead of the groove 106. Thereafter, in the same way, when the oblong hole 111 is consumed, an oblong hole 112 functions as a working groove, and as a result, the working groove for displaying the molten metal removing function exists at all times. Accordingly, a life of the disk 103 is extended, also a cooling effect is improved by forming the oblong holes 111, 112, and a deformation caused by heat can be prevented effectively.