A polycarbonate copolymer, comprising: 0.1 to 50 mol% of a monomer unit represented by a formula as follows; and a monomer unit represented by a formula as follows, wherein the content of a biphenyl compound having three phenolic hydroxyl groups in one molecule is 200 mass ppb or less, which is determined by the method which is provided in the description, where R 1 and R 2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom, where R 3 and R 4 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom; and X represents any one of bonding groups represented by -O-, -S-, -SO-, -SO 2 -, -CO-, 9,9- fluorenylidene group and formulae,, and as follows, where R 5 and R 6 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, R 5 and R 6 being allowed to be bonded together to form a cycloalkylidene group having 4 to 12 carbon atoms, where R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, at least one of R representing an alkyl group having 1 to 3 carbon atoms; where a bonding position is allowed to be any one of o-, m- and p-, and where R 7 to R 12 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a single bonding or a bonding group formed of an alkylene group, on condition that two of R 7 to R 12 each represent a bonding group while the rest of R 7 to R 12 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 0.1 to 50 mol% of a monomer unit represented by a formula as follows; and a monomer unit represented by a formula as follows, wherein the content of a biphenyl compound having three phenolic hydroxyl groups in one molecule is 200 mass ppb or less, which is determined by the method which is provided in the description, where R 1 and R 2 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom, where R 3 and R 4 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom; and X represents any one of bonding groups represented by -O-, -S-, -SO-, -SO 2 -, -CO-, 9,9- fluorenylidene group and formulae,, and as follows, where R 5 and R 6 each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, R 5 and R 6 being allowed to be bonded together to form a cycloalkylidene group having 4 to 12 carbon atoms, where R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, at least one of R representing an alkyl group having 1 to 3 carbon atoms; where a bonding position is allowed to be any one of o-, m- and p-, and where R 7 to R 12 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a single bonding or a bonding group formed of an alkylene group, on condition that two of R 7 to R 12 each represent a bonding group while the rest of R 7 to R 12 each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.