Method for analysing a gas dissolved in an insulating medium of a high-voltage device, wherein the method comprises - transferring the dissolved gas by means of an analysis device into a gas phase to obtain an analysis gas mixture; - transporting the analysis gas mixture to an analysis sensor of the analysis device; - generating a sensor signal as an output signal of the analysis sensor depending on a composition of the analysis gas mixture, wherein the composition of the analysis gas mixture corresponds to a concentration of a gas transferred into a gas phase in the analysis gas mixture; - determining a first intermediate value based on the sensor signal, which depends on the concentration of the gas transferred into the gas phase in the analysis gas mixture, and at least one disturbance value and a further disturbance value, with the aid of a first regression model, wherein the first intermediate value is a concentration of the gas transferred into the gas phase, the concentration being influenced by the disturbance value and the further disturbance value, and the at least one disturbance value comprises a temperature and a moisture content of an environment of the analysis sensor and the further disturbance value comprises a flow velocity of the insulating medium; - determining a second intermediate value based on the first intermediate value and at least one specific value of the analysis device with the aid of a second regression model, wherein the at least one specific value of the analysis device comprises a property of the analysis sensor or the analysis device; and - determining a value for a concentration of the dissolved gas in the insulating medium based on the second intermediate value. - transferring the dissolved gas by means of an analysis device into a gas phase to obtain an analysis gas mixture; - transporting the analysis gas mixture to an analysis sensor of the analysis device; - generating a sensor signal as an output signal of the analysis sensor depending on a composition of the analysis gas mixture, wherein the composition of the analysis gas mixture corresponds to a concentration of a gas transferred into a gas phase in the analysis gas mixture; - determining a first intermediate value based on the sensor signal, which depends on the concentration of the gas transferred into the gas phase in the analysis gas mixture, and at least one disturbance value and a further disturbance value, with the aid of a first regression model, wherein the first intermediate value is a concentration of the gas transferred into the gas phase, the concentration being influenced by the disturbance value and the further disturbance value, and the at least one disturbance value comprises a temperature and a moisture content of an environment of the analysis sensor and the further disturbance value comprises a flow velocity of the insulating medium; - determining a second intermediate value based on the first intermediate value and at least one specific value of the analysis device with the aid of a second regression model, wherein the at least one specific value of the analysis device comprises a property of the analysis sensor or the analysis device; and - determining a value for a concentration of the dissolved gas in the insulating medium based on the second intermediate value.