To provide a conductivity meter capable of stably measuring the conductivity of a liquid to be measured in spite of being manufacturable at low cost.

The conductivity meter 10 measures the conductivity of the liquid 13 to be measured by measuring the resistance value of the liquid 13 between rod-shaped electrodes 2, 3. One of the electrodes is the measuring electrode 2, and the other is the reference electrode 3, and the conductivity meter comprises a guard 4 consisting of an insulating material electrically shielding the electrodes 2 and 3 from the outside. A communicating port 5 for the liquid 13 and a slit 6 are provided in a position C1 near the reference electrode 3 but distant from the measuring electrode 3.