NOVELTY - A conductive polymer (1) has 92% or more of stereoregularity due to coupling scheme (2) of adjacent thiophene rings. The ratio (Mw/Mn) of weight average molecular weight (Mw) and number average molecular weight (Mn) by polystyrene conversion measured by gel permeation chromatography is 1.4 or less. Average repeating number (n) of thiophene ring calculated from Mw is 30-86.    USE - For electric-light converter, electric-electronic element, photoelectric converter and electric circuit board (all claimed).    ADVANTAGE - The conductive polymer has sharp molecular weight distribution and high stereoregularity. The polymer has excellent solubility in organic solvent which enables easy film formation. The thin film formed using the conductive polymer forms effective electroconductive path between polymeric chains in the polymeric chain. The conductive polymer is manufactured inexpensively, safely and easily.    DETAILED DESCRIPTION - The conductive polymer having structure of general formula (1) has 92% or more of stereoregularity due to coupling scheme shown with general formula (2) of adjacent thiophene rings. The ratio (Mw/Mn) of weight average molecular weight (Mw) and number average molecular weight (Mn) by polystyrene conversion measured by gel permeation chromatography is 1.4 or less. Average repeating number (n) of thiophene ring calculated from Mw is 30-86.    R = alkyl group with more than 4 carbons bonded with beta-carbon of thiophene ring;    X,X' = H, chlorine or bromine; and    n = repeating number of thiophene ring.    R = alkyl group with more than 4 carbons.    INDEPENDENT CLAIMS are also included for the following:    (1) Manufacture of conductive polymer by reacting transition metal catalyst containing element chosen from group 10 of periodic table and alkyl thiophene derivative of formula (3);    (2) Electric-light converter;    (3) Electric and electronic element;    (4) Photoelectric circuit board; and    (5) Photoelectric converter.    M = magnesium and zinc;    R = same as above;    DESCRIPTION OF DRAWING(S) - The figure shows the sectional drawing of structure of electric light emitting element using the conductive polymer.    Electrically insulating transparent substrate (1)    Electroconductive transparent electrode (2)    Thin-film layer having charge transport ability and light emission ability (3)    Counter electrode (4)