A radiation-sensitive composition includes a low-molecular-weight compound, a solvent and a radiation-sensitive acid-generator other than the low-molecular-weight compound. The low-molecular-weight compound has one or more acid-dissociable groups which decompose by an action of an acid to enhance solubility in an alkaline developing solution and one or more radiation-sensitive acid-generating groups which generate an acid upon application of an active ray or radiation per molecule. The low-molecular-weight compound has a polystyrene-reduced number-average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 500 to 4,000. The low-molecular-weight compound is not obtained from chain growth polymerization of a monomer with an unsaturated bond. A content of the low-molecular-weight compound is 80 mass % or more of 100 mass % of a total solid component of the radiation-sensitive composition. The low-molecular-weight compound is a compound shown by a following formula (1).