To provide an inspection device capable of suppressing to the utmost occurrence of deficiency such as a parasitic capacity reducing measurement accuracy.

In this inspection device, a coaxial structure is constituted from a metal block 1, an insulating tube 6 mounted on a through hole 3 formed on the metal block 1, and a signal probe 2 inserted into the insulating tube 6, and a contact part to a specimen 7 is provided on one end of the signal probe, and a connection part in contact with a signal wire in a measuring system is provided on the other end, and a probe 4 for GND in contact with the specimen 7 is provided on the metal block 1, and each probe 2, 4 is pressed down onto the metal block 1 by an insulating plate C, to thereby prevent each probe 2, 4 from slipping out from metal block 1. In the device, a space part S having a lowered permittivity is provided by notching the insulating plate C between adjacent probes among the probes 2, 3.