PURPOSE: To eliminate necessity to equip a DC power source which is exlusively used to execute the fusion-cutting of the wire electrode, reduce the manufacturing cost, and execute the down-sizing and weight-saving of the device by making a common use of the DC power source for driving the table and the DC power source for executing the fusion-cutting of the wire electrode.

CONSTITUTION: A wire electric discharge machining device is provided with a DC power source 1 to supply the driving current to a DC servo motor 3, a wire electrode fusion-cutting device 5 connected to the DC power source, and a switch 4 to switch the connection of the DC power source to the wire electrode fusion-cutting device 5. When the table is driven, the switch 4 is opened, and the current from the DC power source 1 is supplied only to a DC servo motor 3. When the fusion-cutting of the wire electrode 9 is executed, the table is stopped, and the driving current to the DC servo motor 3 is suppressed as required to hold the table to the stop position, and the fusion- cutting current is supplied from the DC power source 1 to the wire electrode fusion-cutting device 5 by closing the switch 4.