To provide a cold-cathode ionization vacuum gauge with a longer lifetime.

A cold-cathode ionization vacuum gauge includes: a measuring probe 1 having an anode electrode 11 and cathode electrodes 12a, 12b, 12c; and an electric circuit having a control circuit 3 for controlling a power supply 14 for supplying a voltage (Vd) between the anode electrode 11 and the cathode electrodes 12a, 12b, 12c, a current meter 15 for measuring a current (Id) flowing between the anode electrode 11 and the cathode electrodes 12a, 12b, 12c, and the power supply 14, and successively or continuously changing the voltage (Vd) by constantly adjusting the voltage (Vd) with the change of a pressure (P) such that the voltage (Vd) is increased with an increase of the pressure (P), and that the voltage (Vd) is decreased with a decrease of the pressure (P).

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