A material for forming an adhesive film used for an adhesive film formed directly under a resist upper layer film, contains: (A) a resin having at least one structural unit containing a fluorine-substituted organic sulfonyl anion structure and having at least one structural unit shown by the following general formula (2) besides the structural unit containing the fluorine-substituted organic sulfonyl anion structure; (B) a thermal acid generator; and (C) an organic solvent. The material forms an adhesive film in a fine patterning process by a multilayer resist method in a semiconductor device manufacturing process, where the material gives an adhesive film that has high adhesiveness to a resist upper layer film, has an effect of suppressing fine pattern collapse, and also makes it possible to form an excellent pattern profile. A patterning process uses the material. A method forms the adhesive film. ##STR00001##