Disclosed is a fluorine-containing unsaturated carboxylic acid represented by formula (1), wherein R1 represents a polymerizable double-bond containing group, R3 represents a fluorine atom or fluorine-containing alkyl group, and W represents a bivalent linking group. This compound can provide a fluorine-containing polymer compound that has a weight-average molecular weight of 1,000-1,000,000 and contains a repeating unit represented by formula (2), wherein R3 and W are defined as above, each of R4, R5 and R6 independently represents a hydrogen atom, fluorine atom or monovalent organic group, at least two of R4, R5 and R6 may be combined to form a ring. This polymer compound can provide a chemically amplified resist composition that is transparent to KrF or ArF excimer laser light and has a high resolution and is capable of forming a pattern having a rectangular section with no swelling.