Resist composition and method of forming resist pattern

A resist composition which generates acid upon exposure and exhibits changed solubility in a developing solution under action of acid, the resist composition comprising:

• a resin component (A1) which exhibits changed solubility in a developing solution under action of acid, and
• an acid-generator component (B) which generates acid upon exposure,
• the resin component (A1) comprising a structural unit (a0) represented by general formula (a0-1) shown below,
• the amount of the structural unit (a0) based on the combined total (100 mol %) of all structural units constituting the resin component (A1) being more than 30 mol %, and
• the acid-generator component (B) comprising an acid generator (B1) represented by general formula (b1) shown below:
• wherein, in formula (a0-1), R01 represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms;
• Va01 represents an alkylene group having 1 to 10 carbon atoms;
• Ra01 represents an acid dissociable group;
• in formula (b1), Rb01 represents a cyclic hydrocarbon group of 3 to 20 carbon atoms which may have a substituent;
• Lb01 represents —O—C(═O)— or —C(═O)—O—;
• Yb01 represents a divalent linking group or a single bond;
• Vb01 represents a fluorinated alkylene group having 1 to 9 carbon atoms;
• Rb02 represents a fluorine atom or a hydrogen atom;
• provided that the total number of fluorine atoms contained in Vb01 and Rb02 is 2 or 3;
• m represents an integer of 1 or more;
• and Mm+ represents an m-valent organic cation.