A polymer compound comprising a repeating unit represented by the formula (I): [wherein X1 represents an oxygen atom, a sulfur atom or N(RN)—, R1 to R4 and RN represent a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkynyl 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 or the like.].