An adhesive film including a reactive adhesive capable of curing by heating or light irradiation and a polyphthalide represented by the formula I: ##STR00001## wherein R represents a divalent aromatic hydrocarbon group or a divalent heteroring-containing aromatic group, R.sub.1 represents an alkyl group, a Fluorinated alkyl group, an alkoxy group or a halogen atom, where the number of R.sub.1 is 0 to 4, X represents O or N--R.sub.3, provided that R.sub.3 represents one of the following groups, ##STR00002## Y represents SO.sub.2 or CO and n represents a number of repeating units in the polymer. The adhesive film can be used to connect, e.g., electrodes of a semiconductor chip to electrodes of a wiring board. The polyphthalide can be used to surface-treat, e.g., electrodes of a wiring board.