A
polymer compound comprising a repeating unit represented by the formula (I):[wherein X1 and X2 are the same or mutually different and represent an
oxygen atom, a
sulfur atom, —N(RN)— or C(Rc1)═C(Rc2)—, R1, R2, R3, R4, RN, Rc1 and Rc2 are the same or mutually different and represent a
hydrogen atom, a
halogen atom, an
alkyl group, an
alkoxy group, an alkylthio group, an
aryl group, an aryloxy group, an arylthio group, an arylalkyl group, an arylalkoxy group, an arylalkylthio group, an arylalkenyl group, an arylalkynyl group, a mono-valent heterocyclic group, a heterocyclic
thio group, an amino group, a substituted amino group, a silyl group, a substituted silyl group, an
acyl group, an acyloxy group, an
imine residue, an
amide group, an acid
imide group, a carboxyl group, a substituted carboxyl group, a cyano group or a nitro group, and Ar1 represents a di-valent heterocyclic group.].