Abstract: Provided is a method for preparing a conductive polymer which is highly transparent to visible light in at least one of its conductive and non-conductive states. A solution containing a monomer component and an electrolyte is introduced into an electrochemical cell and subjected to polymerization by cyclic voltammetry. The solution is maintained at a temperature within a range of from 0.degree. to -40.degree. C. inclusive. Prior to the polymerization, cyclic voltammetry is firstly performed at a potential below that at which anodic or cathodic polymerization may take place, anodic and cathodic limits (A) and (B) being held at respective values. A trace of current/voltage is monitored until the trace becomes stable, and thereafter the value of the limit (B) is progressively increased until the said value reaches a critical potential having a magnitude at which anodic or cathodic polymerization is initiated.