The invention relates to a method 100 for determining a pressure in a vacuum system, wherein the method comprises the steps of:



a) generating 101 a plasma in a sample chamber which is fluid-dynamically connected to the vacuum system and which is in electrical contact with a first electrode and a second electrode;
b) measuring 102 a current intensity of an electrical current flowing through the plasma between the first electrode and the second electrode;
c) measuring 103 a first radiation intensity of electromagnetic radiation of a first wavelength range which is emitted from the plasma, wherein the first wavelength range contains at least a first emission line of a first plasma species of a first chemical element;
d) measuring 104 a second radiation intensity of electromagnetic radiation of a second wavelength range which is emitted from the plasma, wherein the second wavelength range contains a second emission line of the first plasma species of the first chemical element or of a second plasma species of the first chemical element, and wherein the second emission line is outside the first wavelength range; and
e) determining 105 the pressure in the vacuum system as a function of the measured current intensity, the measured first radiation intensity, and the measured second radiation intensity. Further, the invention relates to a vacuum pressure sensor.