The review deals with some potentials of chemical modification of interdigitated array microelectrodes with various polymer films; their conductometric and enzyme applications are briefly reviewed. The modification can be performed potentiostatically from a modifier solution until both individually adressable segments are interconnected. The conductivity of polymer immobilized on the electrode surface is influenced by the presence of specific compounds. Electropolymerization of polypyrrole also allows immobilization of enzymes directly in the polymer structure. Conductometric enzyme biosensors can detect products of enzyme reactions due to increasing conductivity of solutions. The method is a powerful tool in analysis of species which play an important role in biochemical processes.