A conjugated polymer consisting of a repeating unit represented by the following formula, wherein said conjugated polymer contains an insolubilizing group as a substituent, and has a weight average molecular weight (Mw) of 20,000 or more and a dispersity (Mw/Mn, here Mn indicates a number average molecular weight) of 2.10 or less: wherein m represents an integer of 0 to 3, each of Ar 11 and Ar 12 independently represents a direct bond, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent, and each of Ar 13 to Ar 15 independently represents an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent, wherein the aromatic hydrocarbon group of Ar 11 to Ar 15 is a group derived from a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzopyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring or fluorene ring, the substituent of the aromatic hydrocarbon group and the aromatic heterocyclic group is one or more selected from the group consisting of an alkyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, a dialkylamino group, a diarylamino group, an arylalkylamino group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, a cyano group, an aromatic hydrocarbon group, and an aromatic heterocyclic group, provided that both Ar 11 and Ar 12 do not represent a direct bond, and said conjugated polymer has, as a substituent, a group containing at least one insolubilizing group in one molecule, wherein said insolubilizing group is a crosslinking group capable of causing an insolubilization reaction by cationic polymerization. wherein m represents an integer of 0 to 3, each of Ar 11 and Ar 12 independently represents a direct bond, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent, and each of Ar 13 to Ar 15 independently represents an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent, wherein the aromatic hydrocarbon group of Ar 11 to Ar 15 is a group derived from a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzopyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluoranthene ring or fluorene ring, the substituent of the aromatic hydrocarbon group and the aromatic heterocyclic group is one or more selected from the group consisting of an alkyl group, an alkynyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, a dialkylamino group, a diarylamino group, an arylalkylamino group, an acyl group, a halogen atom, a haloalkyl group, an alkylthio group, an arylthio group, a silyl group, a siloxy group, a cyano group, an aromatic hydrocarbon group, and an aromatic heterocyclic group, provided that both Ar 11 and Ar 12 do not represent a direct bond, and said conjugated polymer has, as a substituent, a group containing at least one insolubilizing group in one molecule, wherein said insolubilizing group is a crosslinking group capable of causing an insolubilization reaction by cationic polymerization.