A positive resist composition, includes: (A) a compound capable of
generating an acid upon irradiation with actinic rays or radiation; (B) a
resin of which solubility in an alkali developer increases under an
action of an acid, the resin containing 80 mol % or more of an aromatic
group-free copolymerization component; and (C) a compound capable of
decomposing under an action of an acid to generate an acid, wherein an
absolute value of difference in pKa between the acid generated from the
component (A) and the acid generated from the component (C) is 2 or less,
and an absolute value of difference in molecular weight between the acid
generated from the component (A) and the acid generated from the
component (C) is 50 or less.