PURPOSE: To adapt various printed boards by using a prober driving table which has automatic probers whose variable locations are selectively arranged against contact points on wiring as fittable free at the upper side of a printed board.

CONSTITUTION: A prober driving table 11 provided with automatic probers 121W 123 whose contact points within prescribed ranges are varies in directions X and Y selectively is set freely over a printed board 1. The connector terminals of the printed board 1 are connected to a connector 15 and lead wires from the connector 15 are connected to a scanner to perform automatic scanning among those lead wires on the basis of a program in a CPU10. Then, impedance is measured among an optional number of points selected among lead wires 131W133 from the automatic probers 121W123 and the lead wires from the connector 15. The automatic probers 121W123 are positioned by a prober control part 14 according to the kinds of various printed boards 1.