A photographic film cassette has a spool lock mechanism, which is unlocked by a camera member when the film cassette is loaded in a camera. When the unlocked spool is unwound by a camera mechanism, a leader end of a film roll coiled on the spool is advanced outwardly from the interior of the cassette passing through a film passage mouth. When the spool is wound after the photographic film is exposed, the exposed photographic film is wound on the spool. During this winding operation, the film leader end is retained in the film passage mouth by an arresting hook. When the film in the film cassette is not exposed, an indicator shows an unexposed state, but shows an exposed state after the film in the film cassette has been exposed.