A radiation-sensitive resin composition includes a polymer, an acid generating agent, and an organic solvent. The polymer includes a first structural unit derived from a compound represented by a formula (1), and a second structural unit derived from a compound represented by a formula (2). R1 represents an organic group having a valency of (a+2) that represents a ring structure having 3 to 8 carbon atoms together with the carbon atom constituting a lactone ring. R2 represents a fluorine atom, a hydroxyl group, an organic group having 1 to 20 carbon atoms or the like.