The invention relates to a sensor comprising a first metallization plane located on a substrate (1), a passivation layer (6) that is structured by contact holes (7) and is applied to said substrate and a sensitive ceramic layer (9) formed by thick-film technology on the passivation layer and in the contact holes (7). The aim of the invention is to improve the adhesion of the ceramic layer (9). To achieve this, the sensor is provided with an adhesion promoter layer (8) that is configured as a second metallization plane and is located between the passivation layer (6) and the ceramic layer (9).