A vacuum pump for generating an underpressure has a pump chamber (14, 15) with an inlet (143) and an outlet (150), wherein the outlet (150) is equipped with a valve (3). According to the invention, the pump chamber (14, 15) is provided with a pressure sensor (23, 23′, 24). This vacuum pump has a relatively precise and inexpensive vacuum sensor. It is also advantageous that the sensor, being integrated in the pump chamber, is not susceptible to failure and takes up a small amount of space.
