A photoresist composition containing (A) a polymer having a structural unit (I) that includes an acid-labile group, and (I) a compound represented by the following formula (1). In the following formula (1), R1, R2, R3 and R represent a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. X represents a single bond, an oxygen atom or —NRa—. Ra represents a hydrogen atom, a hydroxy group or a monovalent organic group having 1 to 20 carbon atoms, and optionally taken together represents a ring structure by binding with R each other. A− represents —SO3− or —CO2−. M+ represents a monovalent onium cation.