PURPOSE: To increase the relative speed between wire and block unit and improve substantially the efficiency of cutting work, by such means as to rotate the block unit at a prescribed speed while pressing the block unit against the wire.

CONSTITUTION: A cylindrical block unit 20, the objective material to be cut, is adhesively installed as an integral unit by a bonding agent to a mandrel 2A which is fixed to a shaft 9. This shaft 9 is supported by a bearing 9 provided in a prescribed position on a table 6, and a motor 12 is driven to rotate the shaft 9, that is, the block unit 20 in a prescribed direction through a gear 11 and a gear 10. Simultaneously the table 6 is shifted and urged by a dead weight 7 in a vertically upward direction to bring the cylindrical block unit 20 into cotact with a wire 4, causing the relative speed between the wire 4 and the block unit 20 to remarkably increase, thus cutting the block unit 20 efficiently.