Probe unit

A probe unit comprising:

• a plurality of first contact probes each coming into contact with an electrode on one end side in a longitudinal direction;
• a second contact probe connected to an external ground;
• a signal pipe disposed around each of the first contact probes;
• a ground member provided around each signal pipe and configured to form an air layer with the signal pipe;
• a probe holder including
• a plate-shaped first member configured to hold a first end of each of the first and second contact probes, the signal pipe, and the ground member, and
• a plate-shaped second member configured to hold a second end of each of the first and second contact probes, the signal pipe, and the ground member;
• a first wiring part provided at least on a front surface of the first member and electrically connected to the second contact probe;
• a second wiring part provided at least on a front surface of the second member and electrically connected to the second contact probe;
• a first conductive unit configured to electrically connect the first wiring part and the ground member;
• and
• a second conductive unit configured to electrically connect the second wiring part and the ground member.