PURPOSE: To display an exposed state by providing an indicator for the exposed state which is supported so as to move a film from a non-exposure position to an exposure position and making the indicator locking and nonlocking states.

CONSTITUTION: A ring-like unit 101 is provided with the indicator 107 aligned with each mark of a cassette shell 3, when a complete or partial exposure position is obtained. The ring-like unit 101 is in the non-exposure position, a pin 121 is extended into the hole 125 of a cover 109, in a groove 123, to attachably/detachably lock the unit 101 in the non-exposure position. When the pushed part 133 of the unit 101 arranged in the notch 135 of the cover 109 is pushed to thrust the pin 121 into the groove 123, the unit 101 is made free and pushed out of the non-exposure position. Therefore, a spool core is freely rotated in the rewinding direction (and a taking up direction).