A chemically sensitive field effect transistor includes a substrate, a conductor track structure situated on the substrate, and a functional layer which is contacted via the conductor track structure. To be able to form a thin, oxidation-stable and temperature-stable conductor track structure, the conductor track structure is made of a metal mixture which includes platinum and one or more metals selected from the group made up of rhodium, iridium, ruthenium, palladium, osmium, gold, scandium, yttrium, lanthanum, the lanthanides, titanium, zirconium, hafnium, niobium, tantalum, chromium, tungsten, rhenium, iron, cobalt, nickel, copper, boron, aluminum, gallium, indium, silicon, and germanium.