In this study the redox processes of poly(thiophene-3-methanol) modified platinum electrodes were investigated by cyclic voltammetry, in situ optical beam deflection (mirage effect) and Fourier transform IR techniques. The latter two techniques were used in particular to study the insertion and release of ions into and from the polymer film. The electrochemical behaviour of these electrodes was found to be strongly dependent on the sweep rate, electrolyte anion, film thickness and film history, showing a profound relaxation behaviour after storage. The features observed are discussed on the basis of the unique structure of this CH2OH substituted polythiophene which includes both alpha C-alpha C and C-O-C coupled monomers. This structure lowers the degree of conjugation and thus the conductivity of the polythiophene chains, but leads to very compact and adhesive polymer films with application possibilities for example in the fields of microelectronics and corrosion protection.