The present invention relates to a resist composition for practical use with high resolution, high sensitivity, superior pattern profile and no outgas in energy irradiation under high vacuum, suitable to an ultra-fine processing technology represented by use of electron beam and the like, and provides: (1) a resist composition comprising at least one kind of polymer containing, as components thereof, a monomer unit represented by the following general formula [1]: ##STR00001## a monomer unit represented by the following general formula [2]: ##STR00002## and a monomer unit represented by the following general formula [3]: ##STR00003## at least one kind of compound to generate an acid by irradiation of radioactive ray, represented by the following general formula [4]; an organic basic compound; and a solvent, (2) the resist composition in accordance with (1), further containing a polymer unit represented by the following general formula [13]: ##STR00004## and, (3) the resist composition in accordance with (1) and (2), further containing a compound represented by the following general formula [4]: ##STR00005## as a compound to generate an acid by irradiation of radioactive ray.