PURPOSE: To check a printed wiring board pattern without damage by filling a fine-diameter hole provided in a measuring pin with mercury to make a meniscus of mercury from the tip of the fine diameter hole as measuring contact section.

CONSTITUTION: A fine-diameter hole 2 with an opened tip thereof is provided at a measuring pin 1 of a resistance measuring device 7 which performs a continuity test of a printed wiring board or the like and the fine-diameter hole 2 is filled with mercury 3. The mercury 3 is bulged out by a surface tension from the tip of the fine-diameter hole 2 to make a meniscus as a contact section 4 for measurement, which is brought into contact with a pattern of a printed wiring board 5. In addition, the mercury 3 is connected to a measuring circuit body 8 in which a measuring device such as milli-ohm meter. Here, a mercury buildup 9 is formed deep in the fine-diameter hole 2 and measuring pins 1 are made as conductor erected in plurality on a probe substrate and are connected to the measuring circuit body 8 with a conductor 11.