PURPOSE: To discharge stably and measure the degree of vacuum correctly, by furnishing the discharge type vacuum measuring apparatus with current-voltage converting circuit, voltage holding circuit, integrating circuit, and display control circuit.

CONSTITUTION: A control circuit 1 possessing a clock circuit controls the output time of discharge power source 2 to generate high voltage pulses, and the operation of an ingegrating circuit 3a to integrate the time of the outputs of current-voltage converting circuit 3b and voltage holding circuit 3c to hold the output voltage of the current-voltage converting circuit 3b. This current- voltage converting circuit 3b outputs the voltage proportional to the low frequency component of the discharge current, and the integrating circuit 3a detects abnormality in the discharge generation. A display control circuit 10 possesses a switching circuit and a comparator circuit, and an amplifier and compares the outputs of the voltage hold circuit 3c and the integrating circuit 3a through the amplifier, and controls the display circuit 9 by the switching action. The display circuit 9 possesses a voltage self-holding circuit, and displays the degree of vacuum. The abnormality display device 11 displays the state of an abnormality and also controls the control circuit 1.