A chemically amplified resist composition is disclosed which shows a high sensitivity, high resolution, excellent processing adaptability and excellent processing stability, which can form good pattern profile and which is suited as a finely processable material for use in manufacturing integrated circuit elements or the like. The chemically amplified resist composition comprises at least (a) an organic material containing a substituent or substituents capable of being released in the presence of an acid and (b) compounds capable of generating an acid upon exposure to radiation (acid-generators), composed of at least one onium salt and at least one of sulfone compounds and sulfonate compounds. This chemically amplified resist composition preferably further contains a basic compound.