Abstract: A pressure switch for monitoring a tire pressure of a motor vehicle tire is fastened to a wheel rim and is actuated by the inflating pressure in the tire. The pressure switch comprises a reference pressure chamber which is sealed off by an electrically conductive switching diaphragm in the direction of the tire, and carries a contact pin interacting with this diaphragm. The switching diaphragm has a mass which is controlled as a function of centrifugal force in response to tire rotation such that the switching point of the pressure switch can be changed automatically as a function of vehicle speed.