To prevent erroneous detection due to differences in temperature at the time of performing a gas leakage inspections through the use of a digital pressure gauge.

At the time of measuring the pressure of gas and performing leakage inspections, etc., through the use of a digital manometer 1, the temperature of a gas cock 4 is measured as well through the use of a thermocouple 8. A temperature sensor to detect internal temperature is provided in the digital manometer 1 to judge whether the temperature difference with the temperature of the gas cock 4 detected by the thermocouple 8 lies within a predetermined range or not. When the temperature difference is large, the pressure of gas changes from an actual pressure, and measured values change due to changes in temperature with which the manometer 1 approaches a thermal equilibrium state. As such changes are displayed as digital values representing pressure values on a display part 3, the display changes, and there is a possibility of an error detection at the time of the presence of gas leakage. By performing display indicating validity only within the range of a small temperature difference without the possibility of such error detection, it is possible to perform clear discrimination on whether fluctuations in displayed values are due to temperature differences or not.