A polymer represented by the following formula (1):
(A.sub.m).sub.p -(B.sub.n).sub.q -(C.sub.k).sub.r (1)
wherein A represents a monomer unit comprising one of a pyrrole, a
thiophene, a furan, an indole, a carbazole, a benzothiophene, a
dibenzothiophene, a benzofuran, a dibenzofuran, an indolizine, a
thienothiophene, a thienopyrrole and an isoindole; B represents a monomer
unit comprising one of an imidazole, a pyrazole, a pyridazine, a
pyrimidine, a pyrazine, an oxazole, a thiazole, an isooxazole, an
isothiazole, a triazole, a tetrazole, an oxadiazole, a thiadiazole, and a
condensed ring thereof; C represents a monomer unit having a different
structure from the monomer units represented by A and B; m and n each
independently represents an integer of 1 or more; k represents an integer
of 0 or more; p, q and r each independently denotes a mole fraction (%), p
and q represent 1 to 99(%), r represents 0-98(%), the sum of p, q and r is
100(%); and at least one of the monomer units A, B and C comprises as a
substituent at least one group selected from the group consisting of an
alkyl group, an alkoxy group, an ester group, an amide group and a sulfone
amide group, each group having 4 to 20 carbon atoms.
