PURPOSE: To automatically check the wiring width of a signal conductor having the regulation of a current value among printed circuit board wiring pattern.

CONSTITUTION: The current value is previously specified to the signal conductor having the regulation of the current value with regard to logical connection data 10 so that a converting part 13 calculates a wiring width corresponding to the current value at the time of checking. A processing part 14 extracts the signal conductor of which current value is specified and compares the wiring depth corresponding to the specified current value and an actual wiring value so as to check them.