A pattern-forming method includes providing a resist film on a substrate using a radiation-sensitive composition. The resist film is exposed. The exposed resist film is developed using a developer solution. The developer solution includes no less than 80% by mass of an organic solvent. The radiation-sensitive composition includes at least two components including a first polymer and a radiation-sensitive acid generator. The first polymer includes a structural unit having an acid-labile group. One or more components of the radiation-sensitive composition have a group represented by a formula (1). A− represents —N−—SO2—RD, —COO−, —O− or —SO3−. —SO3− does not directly bond to a carbon atom having a fluorine atom. RD represents a linear or branched monovalent hydrocarbon group, or the like. X+ represents an onium cation. -A−X+  (1)