PURPOSE: To enable automatic wiring and to improve workability by deciding the position or the width, etc., of a wiring pattern based on the information of a voltage value to be impressed or a current value to be sent to wiring on a circuit diagram.

CONSTITUTION: This device is equipped with a display 1, keyboard 2, storage device 3 and CPU device 4. In this case, the position or the width, etc., of wiring patterns 5-7 is decided based on the information of the voltage value to be impressed or the current value to be sent to wiring on the circuit diagram. Therefore, even when the levels of voltages to be impressed to the wiring patterns 5-7 are different, the position or the width, etc., of the wiring patterns 5-7 is automatically decided suitably for respective voltage or current values. Thus, manual operations can be unnecessitated and workability can be improved.