Radiation-sensitive resin composition

A radiation-sensitive resin composition comprising

• an acid-labile group-containing resin which is insoluble or scarcely soluble in alkali, but becomes alkali soluble by the action of an acid, and
• a photoacid generator,
• wherein the acid-labile group-containing resin comprises a recurring unit of the following formula (1) and has a ratio of a weight average molecular weight to a number average molecular weight (weight average molecular weight/number average molecular weight) of smaller than 1.5 and is polymerized with a living radical polymerization initiator,
• wherein R1 individually represents a hydrogen atom, methyl group, trifluoromethyl group, or hydroxymethyl group and R2 individually represents a monovalent alicyclic hydrocarbon group having 4-20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1-4 carbon atoms, in which at least one of R2 groups is a monovalent alicyclic hydrocarbon group or a derivative thereof, or any two of R2 groups form a divalent alicyclic hydrocarbon group having 4-20 carbon atoms or a derivative thereof in combination with the carbon atom to which the two R2 groups bond, with the remaining R2 group being a linear or branched alkyl group having 1-4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4-20 carbon atoms or a derivative thereof.