A polymer compound comprising a group represented by the following formula as a side chain connecting to a carbon atom: wherein the benzocyclobutene ring is optionally substituted, and the substituents may connect to each other to form a ring, Ar 1 represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, n represents an integer of 1 to 6, and n Ar 1 s may be the same or different, wherein the polymer compound comprises a repeating unit represented by the following formula : wherein p represents an integer of 1 to 6, q represents an integer of 0 to 3, Ar 21 and Ar 22 each independently represent a direct bond, an optionally substituted aromatic hydrocarbon group, or an optionally substituted aromatic heterocyclic group, Ar 23 to Ar 27 each independently represent an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, R 1 represents a hydrogen atom, an optionally substituted alkyl group having 1 to 24 carbon atoms, an optionally substituted alkoxy group having 1 to 24 carbon atoms, an optionally substituted aromatic hydrocarbon group, or an optionally substituted aromatic heterocyclic group, p Ar 27 s may be the same or different, and q Ar 24 s or q Ar 25 s may each be the same or different, with the proviso that Ar 21 and Ar 22 are not direct bonds at the same time. the benzocyclobutene ring is optionally substituted, and the substituents may connect to each other to form a ring, Ar 1 represents an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, n represents an integer of 1 to 6, and n Ar 1 s may be the same or different, p represents an integer of 1 to 6, q represents an integer of 0 to 3, Ar 21 and Ar 22 each independently represent a direct bond, an optionally substituted aromatic hydrocarbon group, or an optionally substituted aromatic heterocyclic group, Ar 23 to Ar 27 each independently represent an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, R 1 represents a hydrogen atom, an optionally substituted alkyl group having 1 to 24 carbon atoms, an optionally substituted alkoxy group having 1 to 24 carbon atoms, an optionally substituted aromatic hydrocarbon group, or an optionally substituted aromatic heterocyclic group, p Ar 27 s may be the same or different, and q Ar 24 s or q Ar 25 s may each be the same or different, with the proviso that Ar 21 and Ar 22 are not direct bonds at the same time. Ar 23 to Ar 27 each independently represent an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, R 1 represents a hydrogen atom, an optionally substituted alkyl group having 1 to 24 carbon atoms, an optionally substituted alkoxy group having 1 to 24 carbon atoms, an optionally substituted aromatic hydrocarbon group, or an optionally substituted aromatic heterocyclic group, p Ar 27 s may be the same or different, and q Ar 24 s or q Ar 25 s may each be the same or different, with the proviso that Ar 21 and Ar 22 are not direct bonds at the same time. <EOS>