Abstract: The invention relates to a polymeric corrosion inhibiter for a metal substrate of formula (R1)aA(R2X)b, where a=0-3, b=1-6, A is a bridge structure unit, R1 is identical to or different from H or an aliphatic, aromatic, olefinic, cyclic, heterocyclic, polycyclic or polyheterocyclic radical, R2 is identical to or different from a polymeric basic structure, X is identical to or different from a functional group selected from the groups comprising: carboxylic acids; dicarboxylic acids; polycarboxylic acids; carboxylic acid anhydrides; carboxylic acid chlorides; carboxylic sulfonic acids; and also esters, amides and imides of the aforementioned groups, the molar mass of the polymer lies between 200 and 10,000, preferably 400 and 6,000. The invention further relates to the use of a polymeric corrosion inhibiter for the treatment of metal surfaces and to a method for producing a polymeric corrosion inhibiter.