A (meth)acrylic copolymer comprising: a constitutional unit having a triorganosilyloxycarbonyl group; and a constitutional unit derived from a macromonomer (b): wherein the macromonomer (b) is a compound which has a radically polymerizable group and two or more constitutional units derived from a monomer having a radically polymerizable group, and, wherein the macromonomer (b) is a macromonomer having two or more constitutional units represented by the following formula (b'): (where, R 41 represents a hydrogen atom, a methyl group, or CH 2 OH and R 42 represents OR 43, a halogen atom, COR 44, COOR 45, CN, CONR 46 R 47, or R 48, where R 43 to R 47 each independently represent a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, an unsubstituted or substituted nonaromatic heterocyclic group, an unsubstituted or substituted aralkyl group, an unsubstituted or substituted alkaryl group, or an unsubstituted or substituted organosilyl group and R 48 represents an unsubstituted or substituted aryl group or an unsubstituted or substituted heteroaryl group). a constitutional unit having a triorganosilyloxycarbonyl group; and a constitutional unit derived from a macromonomer (b): wherein the macromonomer (b) is a compound which has a radically polymerizable group and two or more constitutional units derived from a monomer having a radically polymerizable group, and, wherein the macromonomer (b) is a macromonomer having two or more constitutional units represented by the following formula (b'): (where, R 41 represents a hydrogen atom, a methyl group, or CH 2 OH and R 42 represents OR 43, a halogen atom, COR 44, COOR 45, CN, CONR 46 R 47, or R 48, where R 43 to R 47 each independently represent a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, an unsubstituted or substituted nonaromatic heterocyclic group, an unsubstituted or substituted aralkyl group, an unsubstituted or substituted alkaryl group, or an unsubstituted or substituted organosilyl group and R 48 represents an unsubstituted or substituted aryl group or an unsubstituted or substituted heteroaryl group). wherein the macromonomer (b) is a compound which has a radically polymerizable group and two or more constitutional units derived from a monomer having a radically polymerizable group, and, wherein the macromonomer (b) is a macromonomer having two or more constitutional units represented by the following formula (b'): (where, R 41 represents a hydrogen atom, a methyl group, or CH 2 OH and R 42 represents OR 43, a halogen atom, COR 44, COOR 45, CN, CONR 46 R 47, or R 48, where R 43 to R 47 each independently represent a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted alicyclic group, an unsubstituted or substituted aryl group, an unsubstituted or substituted heteroaryl group, an unsubstituted or substituted nonaromatic heterocyclic group, an unsubstituted or substituted aralkyl group, an unsubstituted or substituted alkaryl group, or an unsubstituted or substituted organosilyl group and R 48 represents an unsubstituted or substituted aryl group or an unsubstituted or substituted heteroaryl group).