PURPOSE: To make each contactor correspond flexibly to make it possible to bring the contactor into contact with an external circuit accurately, reliably and electrically by a method wherein connection conductors which connect connecting terminals to through holes corresponding to each other, are formed on a printed circuit board.

CONSTITUTION: A printed circuit board 11 formed with a multitude of through holes 12 and a conductive sphere-shaped microcontactor 14, which is pressed and fixed into the side of one end of each of these holes 12, are provided. Connecting terminals and connection conductors 13, which connect these terminals to the holes 12 corresponding to each other, are formed on the upper surface of the board 11. The terminals are provided at proper places on the upper surface of the board 11 and do the working of the connection of an electrical wiring with an aging tester. These of the holes 12, the terminals and the connection conductors 13 are easily formed by a normal printed wiring method.