Abstract: An instant photo film pack has a pack body, which has a small thickness and has first and second walls opposed to each other, and contains a stack of plural self-developing photo film units. An exposure opening is formed in the first wall, and provides each of the photo film units with an exposure. An exit slit is formed in the pack body, disposed in an advancing direction, for exiting each of the photo film units. A light-shielding cover sheet closes the exposure opening in a light-tight manner, to be exited through the exit slit by an external operation. Two dimple-formed deformed portions are disposed on the light-shielding cover sheet to project toward the photo film units, and prevents a first photo film unit among the photo film units from passing the exit slit while the light-shielding cover sheet is exited, the first photo film unit being directly behind the light-shielding cover sheet.