A probe unit includes: a plurality of first contact probes each coming into contact with an electrode to be contacted on one end side in a longitudinal direction; a second contact probe connected to an external ground; and a probe holder configured to hold the first and second contact probes, the probe holder including a first hollow portion configured to allow the first contact probes to be inserted therethrough and hold the first contact probes, a second hollow portion configured to allow the second contact probe to be inserted therethrough and hold the second contact probe, and a through-hole provided around the first hollow portion, wherein the probe holder includes a conductive portion that constitutes the through-hole and electrically connects the through-hole and the second contact probe.