To discriminate the abnormality of a pump main body from the abnormality of an exhaust port side in a vacuum pump.

This vacuum pump is provided with a rotation detector 6 for genrating a pulse in proportion to the rotation speed of the motor of a vacuum pump, a frequency voltage converter 20 for converting to a voltage value in proportion to the rotation speed, a standard voltage generator 30 for generating a standard voltage value in response to the allowable rotation speed of the motor, a first abnormality detector 50 for detecting the abnormality of a pump in comparison with the voltage value and standard voltage value, a pressure detector 7 for detecting the exhaust pressure of the exhaust port side of the vacuum pump and a second abnormality detector 51 for detecting the abnormality of the exhaust port side in comparison with the exhaust pressure and the standard pressure. A pump main body is monitored by monitering the rotation speed of the motor and the exhaust port side is monitored by monitering the pressure of the exhaust port and the abnormality detection of the exhaust port side is carried out at the abnormality detection time of the motor and when the abnormality is detected on the exhaust port side by this abnormality detection, the abnormality of the exhaust port side is judged and when the abnormality is not detected in the exhaust port side, the abnormality of the pump main body is judged.