A negative pattern is formed by coating a resist composition comprising a polymer comprising recurring units of acid labile group-substituted vinyl alcohol and maleic anhydride and/or maleimide, an acid generator, and an organic solvent onto a substrate, prebaking, exposing to high-energy radiation, and developing in an organic solvent developer such that the unexposed region of resist film is dissolved away and the exposed region of resist film is not dissolved. In image formation via positive/negative reversal by organic solvent development, the resist film is characterized by a high dissolution contrast between the unexposed and exposed regions.