PURPOSE: To deposit an electrode component in a working gap as well as to attempt the prevention of movement/falling down of a work piece by providing a judging circuit driving a switching element and a short and a long pulse wave form oscillator to an ordinary circuit whereby switching over pulse by a command signal.

CONSTITUTION: A judging circuit 7 driving a switching element 5 is provided to an ordinary circuit including a direct current power source 1, a current limiting resistor 3, a switching element 5, a wire electrode E, and a work piece W and the like. When a supply command signal 9 of a short pulse wave form or a long pulse wave form is inputted into said circuit, pulses from a short pulse oscillator 11 or a long pulse oscillator 13 are sent to the switching element 5. And the short pulse oscillator 11 is used for an ordinary work, however, when bonding is required, the drive of the switching element 5 is changed over to the long pulse oscillator 13 by a command signal 9 whereby an electrode component is deposited on a working gap. Owing to this constitution, the falling down of the work piece is automatically prevented.