A film cassette assembly has a cassette and a roll of film wound on a spool and contained in the cassette. When the spool is rotated, the roll of film is rotated together with it in order to feed a film leader out of the cassette through a film passage mouth. To rotate the spool and the roll of film together, the film cassette assembly presses an axial end portion of the outermost periphery of the roll of film or presses the film's circumferential peripheral surface. Where the axial end portion of the outermost periphery of the roll of film is to be pressed, at least one of a pair of flanges of the spool is elastically deformed to clamp both axial side edges of the outermost periphery of the roll of film. Where the circumferential surface of the outermost periphery of the roll of film is to be pressed, a projection and an elastic member are provided within the cassette.