The present invention provides a film adhesive comprising, as the main constituent, a polyimide resin having a glass transition temperature of 350.degree. C. or lower and soluble in organic solvents, which polyimide resin is obtained by reacting at least one of the following acid components (A) and (B) (A) 4,4'-oxydiphthalic acid dianhydride (B) 3,3',4,4'-biphenyltetracarboxylic acid dianhydride and/or 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride with at least one of the following amine components (C) and (D) (C) a siloxane compound represented by the following general formula (1) and/or 2,2-bis(4-(4-amino-phenoxy)phenyl)propane ##STR1## wherein R.sub.1 and R.sub.2 are each a bivalent aliphatic (C.sub.1-4) or aromatic group; R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are each a mono-valent aliphatic or aromatic group; and k is an integer of 1-20, (D) bis(aminophenoxy)benzene and/or dimethylphenylene-diamine to give rise to ring closure of imide, as well as a process for producing said film adhesive.