There is disclosed a sulfonium salt represented by the following general formula (1). In the formula, X and Y each represents a group having a polymerizable functional group; Z represents a divalent hydrocarbon group having 1 to 33 carbon atoms optionally containing a hetero atom; R1 represents a divalent hydrocarbon group having 1 to 36 carbon atoms optionally containing a hetero atom; and R2 and R3 each represents a monovalent hydrocarbon group having 1 to 30 carbon atoms optionally containing a hetero atom or R2 and R3 may be bonded with each other to form a ring together with a sulfur atom in the formula. There can be provided a sulfonium salt usable as a resist composition providing high resolution and excellent in LER in photolithography using a high energy beam such as an ArF excimer laser, an EUV light and an electron beam as a light source, a polymer obtained from the sulfonium salt, a resist composition containing the polymer and a patterning process using the resist composition.