Resist composition and method of forming resist pattern

A resist composition which generates an acid upon exposure and whose solubility in a developing solution is changed due to an action of the acid, the resist composition comprising:

• a base material component (A) whose solubility in a developing solution is changed due to the action of an acid;
• and
• an acid generator component (B) which generates an acid upon exposure,
• wherein the base material component (A) contains a polymer compound (A1) having a constitutional unit (a0) represented by Formula (a0-1), and
• wherein the acid generator component (B) contains a compound (B1) represented by Formula (b1):
• wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms;
• Va° represents a divalent hydrocarbon group which may have a substituent;
• nao represents an integer of 0 to 2;
• and Ra00 represents an acid dissociable group represented by Formula (a0-r1-1):
• wherein Ra01 and Ra02 each independently represent a hydrocarbon group which may have a substituent;
• Ra01 and Ra02 may be bonded to each other to form a ring structure;
• Ya° represents a quaternary carbon atom;
• and Ra031, Ra032, and Ra033 each independently represent a hydrocarbon group which may have a substituent, and two or more of Ra031, Ra032, and Ra033 may be bonded to one another to form a ring structure,
• wherein Rb1 represents a monovalent hydrocarbon group which has a steroid skeleton and 17 to 50 carbon atoms, where the steroid skeleton contains at least one hydroxyl group and may have a substituent other than the hydroxyl group;
• Yb1 represents a divalent linking group having a hetero atom or a single bond;
• Vb1 represents an alkylene group, a fluorinated alkylene group, or a single bond;
• Rf1 represents a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms, m represents an integer of 1 or greater, and Mm+ represents an m-valent organic cation.