A film for a circuit board, characterized in that it comprises the following A layer and B layer which are adjacent to each other: A layer: a heat−resistant resin layer having a thickness of 2 to 250 μm which comprises a heat−resistant resin having a glass transition temperature of 200˚C or higher or a decomposition temperature of 300˚C or higher, and B layer: a cured resin layer capable of being roughened which has a thickness of 5 to 20 μm and comprises a thermoset product derived from a thermosetting resin composition comprising the component (a) of an epoxy resin having two or more epoxy groups in one molecule thereof and the component (b) a curing agent for an epoxy resin and capable of being roughened by the use of an oxidizing agent. The film allows the production of a circuit board being excellent in the adhesion strength of a conductive layer with ease and simplicity.