To highly precisely measure an electric characteristic of a specimen, without bringing contact failure between a measuring substrate and a probe card even when used for a long period.

An insertion-locking part 22 of a guide frame 21 with the probe card 31 inserted and positioned is inserted into a locking hole 12 of the measuring substrate 11 from its lower side, and rotated to attach the guide frame 21 to the substrate 11. An electrode 18 of the substrate 11 is provided with a slope 14 sloped upwards from a lower face of the substrate 11 toward a rotational direction of the probe card 31, and is arranged on a horizontal pane 15 continued to the slope 14 inside a groove 13 formed with a width through which a conductive pin 38 of the probe card 31 is allowed to be moved.