Abstract: The invention relates to an optochemical sensor comprising a polymer matrix which is applied to a substrate and which is doped with a luminescent colorant, the emissivity of which can be modified after excitation with electromagnetic radiation by substances to be detected such as gaseous or dissolved O2, SO2, H2O2, CO2, nitrogen oxides and halogenated hydrocarbons, which polymer matrix forms a sensor layer that is also covered by an optical insulating and protective layer which can be permeated by the substance to be analysed. In the optochemical sensor, the sensor layer is formed from a layer which has an insular sensor element or a plurality of mutually separated sensor elements, the at least one sensor element being covered by a non-doped polymer matrix which chemically corresponds to the polymer matrix of the sensor layer.