According to one embodiment, an actinic-ray- or radiation-sensitive resin composition includes (A) a resin that when acted on by an acid, increases its solubility in an alkali developer, (B) a compound that when exposed to actinic rays or radiation, generates an acid, and (C) a resin containing at least one group selected from among the following groups (x) to (z) and further containing at least either a fluorine atom or a silicon atom, in which three or more polymer chains are contained through at least one branch point, (x) an alkali-soluble group, (y) a group that when acted on by an alkali developer, is decomposed to thereby increase its solubility in the alkali developer, and (z) a group that when acted on by an acid, is decomposed to thereby increase its solubility in an alkali developer.